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Biomedical subjects

M Fukuchi

Publications and source records attributed to M Fukuchi.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Factors influencing exercise tolerance in patients with myocardial infarction as elucidated by Tl-201 myocardial scintigraphy].

Measurements of O2 consumption during treadmill exercise tests and Tl-201 myocardial scintigraphy were performed in 17 cases of myocardial infarction to elucidate O2 consumption at an anaerobic threshold ATVO2 as an adequate index of exercise tolerance, and the scintigraphic indices influencing the exercise tolerance. ATVO2 was obtained using the method of Wasserman and Davisand corrected by body weight. The scintigraphic indices such as the location, extent (residual myocardium), and severity (% uptake) of myocardial infarction were obtained from SPECT and bull's eye displays on Tl-201 myocardial scintigraphy. ATVO2 was correlated with theoretical VO2max as obtained by the predicted maximal heart rate (r = 0.56, p less than 0.01) and with left ventricular ejection fraction as obtained by radionuclide left ventriculography (r = 0.59, p less than 0.01). There was no significant difference between ATVO2 in cases of anterior wall infarction and those of inferior (and/or lateral wall) infarction. There was no significant correlation between % uptake and ATVO2. However, the residual myocardium showed a significant correlation with ATVO2 (r = 0.61, p less than 0.01). In conclusion, 1) ATVO2 is an adequate index of exercise tolerance and reflects cardiac function. 2) The extent of the residual myocardium is most strongly influenced by ATVO2 among the indices of myocardial damage as obtained by Tl-201 myocardial scintigraphy.

Adaptation, Physiological↗
PubMed1988

[Indications for coronary revascularization and the postoperative evaluations using Tl-201 exercise myocardial scintigraphy and a bull's eye display].

Tl-201 exercise myocardial scintigraphy and quantitative analysis using bull's eye display were performed in 31 cases (18 bypass cases, 13 PTCA cases) to determine the indications for coronary artery bypass surgery and PTCA, and to evaluate postoperative improvement. Regions of interest (ROI) corresponding to each revascularized area were created on a bull's eye display. Then the washout rates (WR) and % uptakes were expressed as percentages. Improvement was judged to have occurred if the revascularized coronary artery was patent and both the WR and % uptake returned to the normal range as determined from the examinations of 20 normal cases. The results were as follows: 1. The preoperative mean WR of the improved areas (30 vessels) was 19 +- 15%, while that of the unimproved areas (15 vessels) was 35 +- 7%. We assumed that the area was suitable for revascularization when the preoperative WR was less than 25% which was in the lower limit of the normal range. Then, 18 vessels were judged to be suitable for surgery, and subsequent postoperative improvement was obtained in the 17 areas. 2. In 32 scintigraphically-improved areas, 30 vessels were angiographically patent, while five vessels were obliterated angiographically in 13 scintigraphically-unimproved areas (diagnostic validity was 76% of all 45 vessels). 3. The exercise tolerance increased significantly (p less than 0.01) from 8.7 +- 2.0 min to 11.6 +- 2.5 min in the improved cases in which all the revascularized areas were improved after revascularization. There was no change of the exercise tolerance (before: 9.4 +- 3.4 min, after: 9.4 +- 2.5 min) in the unimproved cases in which all the revascularized areas were unimproved. 4. Quantitative analysis was useful for objective evaluation, because the visual evaluations did not always agree with the quantitative evaluation. We concluded that the area with the preoperative WR less than the normal range is suitable for revascularization. As the scintigraphic evaluation was in accord with improved exercise tolerance and with patency as observed by coronary angiography, our method seems useful for postoperative follow-up.

Angioplasty, Balloon↗
PubMed1987

[Infarct size determined by emission computed tomography using 99mTc-PYP: effect of coronary thrombolysis].

Emission computed tomography with 99mTc-PYP was used to estimate infarct size in 38 patients with documented acute myocardial infarction. In the present study, the effect of thrombolysis with Urokinase on infarct size and on left ventricular function was assessed. Fourteen patients with acute myocardial infarction who underwent intracoronary thrombolysis within six hours after the onset of symptoms, and 24 patients who underwent conventional therapy were the subjects of this study. Infarct size was measured by drawing a region of interest around the myocardial pyrophosphate uptake for each tomographic slice. The boundary was then defined as 65% of the maximal count within the region of interest as determined by phantom volume studies. The total number of voxels was obtained by adding those in all slices and multiplying the sum by the voxel volume (0.205 ml per one voxel) to determine the infarct volume. Measurement of the 99mTc-PYP uptake on the tomographic image revealed an average infarct size of 100.1 +/- 36.0 ml (ranged 45 to 198). The calculated infarct volume correlated significantly with sigma CPK (p less than 0.01) and with left ventricular ejection fraction (p less than 0.01), but not with the peak CPK. In patients with acute inferior myocardial infarction, the mean infarct volume was 78.4 +/- 29.1 ml in the coronary thrombolysis group, and 105.1 +/- 33.7 ml in the conventional bypass graft treatment group (p less than 0.05). We concluded that successful intracoronary thrombolysis may reduce infarct size. ECT imaging with 99mTc-PYP to determine infarct size may be clinically applicable in patients with acute myocardial infarction.

Adult↗
PubMed1987

[Right ventricular ejection and regional wall motion evaluated by cardiac blood pool emission computed tomography].

Calculating right ventricular (RV) ejection fraction (EF) is difficult because of geometrical problems such as irregular trabeculations, a separate infundibulum, and variations in the right ventricular shape. We performed 99mTc ECG-(dual)gated cardiac blood pool emission computed tomography (ECT) in 10 patients with ischemic heart disease, three patients with dilated cardiomyopathy (DCM), and eight normal subjects as controls, and RVEF and % shortening of the RV were calculated to evaluate right ventricular function. Methods were as follows: 1) RVEF: The region of interest (ROI) of the RV was determined on reconstructed short-axial images, and then the RV counts in the ROI were summed from the apical slice to the RA-RV boundary slice. (Formula: see text) 2) % shortening of the RV: At the RV mid-portion, the contour from the short-axial image was obtained using the threshold method; the end-diastolic contour was superimposed on the end-systolic contour, and then shortenings in the RV free wall and septum respectively, were calculated. To evaluate reliability of RVEF obtained by this method, left ventricular ejection fraction (LVEF) calculated using the same method was compared with results obtained by the previously validated method: There were significant correlations with contrast cineangiography (r = 0.69) and the conventional multigated method (r = 0.90), respectively. Cases with decreased RVEF showed a variety of right ventricular abnormal findings, including positive uptake on 99mTc-PYP scintigraphy, occlusion of the right coronary artery, RV dilatation on echocardiography. The mean RV free wall shortening in the decreased RVEF group was lower than that of the normal group (p less than 0.01), whereas there was no significant difference in the decreased LVEF group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Gonadotropin and testosterone response in prepubertal boys with hypospadias.

Serum levels of luteinizing hormone and follicle-stimulating hormone before and after luteinizing hormone-releasing hormone stimulation, and levels of testosterone before and after 3 days of treatment with human chorionic gonadotropin were determined by radioimmunoassay in 98 boys with hypospadias (2 to 8 years old). The doses of luteinizing hormone-releasing hormone and human chorionic gonadotropin were calculated for body surface. The basal and peak levels of serum luteinizing hormone, follicle-stimulating hormone and testosterone in patients with hypospadias were compared with 9 endocrinologically normal boys of the same age without hypospadias. Luteinizing hormone response to luteinizing hormone-releasing hormone stimulation was significantly impaired in boys with hypospadias and also simple hypospadias (no associated anomaly). Basal levels of luteinizing hormone in boys with simple hypospadias and levels of follicle-stimulating hormone in patients with hypospadias were significantly low. The maximum testosterone response to human chorionic gonadotropin stimulation was significantly decreased in boys with severe hypospadias in direct proportion to the degree of hypospadias.

Child↗
PubMed1986

[Left ventricular asynergy detected by cardiac blood pool emission computed tomography using the subtraction method].

To evaluate left ventricular regional wall motion, ECG dual-gated cardiac blood pool ECT was performed for 25 patients with ischemic heart disease, including 19 cases of myocardial infarction, five cases of angina pectoris, and one case of post A-C bypass surgery. There were six normal controls. Following SPECT obtained using 32 views (180 degrees), the vertical and horizontal long axes were reconstructed from transaxial images. Then, regional wall motion was evaluated from subtraction images; (end-diastolic)-(end-systolic) and (end-systolic)-(end-diastolic) images. SPECT images were compared with left ventriculography (LVG); vertical long-axial ECT images with segments 1-5 of LVG by the AHA classification, and horizontal ECT long-axial images with segments 6 and 7 of LVG, respectively. The subtraction images from ECG dual-gated cardiac blood pool ECT corresponded with left ventriculography in 79.4% of 175 segments in 25 patients with ischemic heart disease (sensitivity 92.6%, specificity 68.0%, and accuracy 79.4%). When wall motion was classified as normal, hypokinesis, akinesis, and aneurysmal, good agreement was observed between the two methods in 68% of these segments. The locations of asynergy as obtained by this method were closely in accord with those of perfusion defects by Tl-201 myocardial SPECT in 74.4% of segments. Left ventricular aneurysms were detected using subtraction image; (end-systolic)-(end-diastolic). We conclude that this subtraction method is useful for evaluating left ventricular asynergy.

Adult↗
PubMed1984

Somatostatin-like immunoreactivity in rat thyroid. Age-associated S-cell hyperplasia.

Somatostatin-like immunoreactive cells of the rat thyroid gland at various ages were investigated immunohistochemically. The number of cells per lobe in 5 micron sections increased with age. Immunopositive cells were evident as small clusters in the older age group (8 to 24 months old) but not clustered in the younger age group (3 to 5 months old). This type of proliferation was termed S-cell hyperplasia in a manner similar to C-cell hyperplasia observed in the aged rat thyroid.

Aging↗
PubMed1984

Malignant pheochromocytoma with ACTH production.

An autopsy case of a 54-year-old woman with malignant pheochromocytoma and ectopic ACTH production was reported. Noradrenaline was increased in 24 hour urine and in the blood sample from the left adrenal vein. Hormone assay studies of the tumor tissue and plasma revealed abnormally high levels of ACTH. Formaldehyde fume induced fluorescence method demonstrated biogenic amine in the tumor cytoplasm. Electron microscopic examinations also disclosed numerous neurosecretory granules in the tumor cytoplasm. These findings confirmed that this pleomorphic carcinoma of the left adrenal gland was one of the APUDoma originating from the adrenal medulla, so-called pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1984

Primary C cell hyperplasia of the thyroid in Fischer 344 rats. An immunohistochemical study.

C cell proliferation of the thyroid, which was designated as primary C cell hyperplasia (PCCH), was demonstrated in aged Fischer 344 rats in high incidence using the immunohistochemical method for calcitonin. It developed from mild to severe PCCH and resulted in nodular PCCH and tumor formation. The combined incidence of PCCH and nodular PCCH was increased with age and appeared in 60.7% of 7-15 month old group and 92.7% of 16-24 month old group possibly as a preneoplastic C cell lesion. It is almost an equivalent C cell lesion reported in the human thyroid with familial C cell carcinoma and therefore this Fischer 344 rat can provide a useful animal model to study familial C cell tumor of the thyroid.

Animals↗