Biomedical subjects
Publications and source records attributed to A Azuma.
The antitumor activity, cellular metabolism and mechanism of action of the antitumor nucleoside analog, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd) are described.
Exercise 201Tl myocardial scintigraphy of patients with apical hypertrophic cardiomyopathy (AH) often shows transient perfusion defect in the apex. Catecholamine may be related to the pathogenesis of AH, but this is not certain. The relationship between hypertrophy, myocardial ischemia, and cardiac sympathetic nervous function were investigated by comparing 123I-MIBG myocardial SPECT with exercise 201Tl myocardial SPECT especially at the apex which is the hypertrophic region. Seventeen patients with AH, mean age of 53 +/- 11 years old, underwent 123I-MIBG myocardial SPECT and exercise 201Tl myocardial SPECT on separate days. Decreased tracer uptake regions and the severity and extent of the defect were evaluated visually and compared. Myocardial clearance of 123I-MIBG in apical, midventricular, and basal regions was calculated from the bull's eye display. 123I-MIBG SPECT showed a decreased uptake or defect in the apex of all patients. 201Tl SPECT showed a reversible perfusion defect in the apex of 10 patients, an irreversible perfusion defect in the apex in 3, and normal perfusion in 4. Comparing decreased uptake on the exercise 201Tl myocardial image and 123I-MIBG 4-hour delayed image, the severity of the defect was: MIBG > Tl in 12 patients (71%), MIBG = Tl in 5 (29%), and the extent of the defect was: MIBG > Tl in 11 (65%), MIBG = Tl in 6 (35%). Mean clearance of 123I-MIBG in the apical and midventricular regions was significantly higher than that in the basal region (apical 46.2 +/- 7.1%, midventricular 44.4 +/- 7.8%, basal 38.7 +/- 7.7%).(ABSTRACT TRUNCATED AT 250 WORDS)
The effect of verapamil on myocardial ischemia in patients with hypertrophic cardiomyopathy (HCM) was evaluated by exercise myocardial 201Tl SPECT (EX-Tl). EX-Tl was performed before and after 8.1 +/- 6.1 weeks of oral administration of verapamil (240 mg/day) on 20 patients with HCM who showed transient 201Tl perfusion defects under control conditions. SPECT images were divided into nine segments. The 201Tl perfusion defect was visually scored and evaluated for four grades in each segment and the sum total grade was calculated as the defect score. Transient dilation index was calculated as a reflection of subendocardial ischemia. Improvements in defect score were demonstrated in 18 of 20 patients after administration of verapamil. The mean defect score decreased significantly from 5.1 +/- 2.3 to 2.5 +/- 2.4 (p < 0.001). Although 18 of 20 patients showed abnormal transient dilation index under control conditions, 16 showed improvement and 12 were normalized after verapamil therapy. Mean transient dilation index decreased from 1.24 +/- 0.19 to 1.08 +/- 0.10 (p < 0.01). Verapamil improves myocardial ischemia in patients with HCM.