Biomedical subjects

Yasushi Kitaura

Publications and source records attributed to Yasushi Kitaura.

41 records · Page 3Linked to original sources

PubMed2002

CD36 genotype and long-chain fatty acid uptake in the heart.

Homozygous or compound heterozygous mutation of the CD36 gene (CD36-/-) in humans results in severe defects of the uptake of long-chain fatty acids (LCFAs) in the heart. Because the effect of a single mutation of this gene (CD36+/-) on the LCFA uptake is not known, it was evaluated in 29 subjects with the CD36 wild-type gene (WT) (6 healthy subjects, 10 patients with heart disease), CD36+/- (4 healthy subjects, 5 patients) and CD36-/- (4 patients). The CD36 genotype was identified in the coding region of genomic DNA, and the expression of CD36 protein was examined by flow cytometry after staining with monoclonal anti-CD36 antibody. The LCFA uptake in the heart was assessed as the radioactivity accumulation ratio of heart to mediastinum after intravenous administration of iodine-123 15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid (H/M ratio). The H/M ratios in WT, CD36+/- and CD36-/- were 2.28 +/- 0.10, 1.90 +/- 0.06 and 1.40 +/- 0.11, respectively (p < 0.0001, among groups). The H/M ratio between healthy subjects and patients with heart disease for WT and CD36+/- did not differ significantly (ie, those of WT and CD36+/- in healthy subjects and patients were 2.29 +/- 0.08 vs 2.27 +/- 0.12 and 1.90+/- 0.07 vs 1.89 +/- 0.05, respectively). Not only CD36-/- but also CD36+/- resulted in a significant reduction of the LCFA uptake in the heart independent of heart disease, suggesting genotype dependency and that CD36 might be a fundamental determinant of myocardial LCFA uptake.

Adult↗

PubMed2002

Prediction of functional recovery of the left ventricle after coronary revascularization in patients with prior anterior myocardial infarction: a myocardial integrated backscatter study.

Cyclic variation (CV) of myocardial integrated backscatter (IBS), which reflects intrinsic contractile performance, can predict myocardial viability in patients with a reperfused acute myocardial infarction (MI), but the use of this method has not been validated for chronic left ventricular (LV) dysfunction. The aim of this study was to examine whether myocardial IBS was useful for predicting LV functional recovery after coronary revascularization in 17 patients with prior anterior MI and LV dysfunction (ejection fraction <50%). Within 24 h of the revascularization procedure (percutaneous transluminal coronary angioplasty or coronary stenting), IBS curves were obtained by placing the region of interest on the anterior wall on the short-axis IBS image. The patients had repeat left heart catheterization at 3 or 6 months after the revascularization procedure, and were grouped according to the patterns of the IBS curve within the anterior wall. In 8 patients (group A), the IBS curve had a synchronized pattern with the magnitude of CV > or = 3.5, and in the remaining 9 patients (group B), the curve had either an asynchronized pattern or the magnitude of CV was less than 3.5 dB even in the case of synchronized pattern, or both. At baseline, there were no significant differences in LV functional indices between the 2 groups. After the follow-up period, the LV end-systolic volume decreased (75 +/- 21 ml to 56 +/- 20ml, p = 0.05), LV ejection fraction increased (35 +/- 12% to 50 +/- 14%, p = 0.014), and LV end-diastolic pressure decreased (19 +/- 10 mmHg to 13 +/- 6 mmHg, p = 0.02) in group A, whereas only the LV ejection fraction increased (34 +/- 9% to 40 +/- 11%, p = 0.03) in group B; LV end-systolic volume (72 +/- 19 ml to 66 +/- 16 ml, p = 0.126) and LV end-diastolic pressure (18 +/- 12 mmHg to 14 +/- 8 mmHg, p = 0.184) showed no significant changes. In conclusion, IBS is valuable for predicting LV functional recovery after coronary revascularization in patients with LV dysfunction caused by a remote anterior MI. A large-scale study is be needed to establish these data.

Aged↗

PubMedDate not supplied

Comparative study of quantitative blood pool SPECT imaging with 180 degrees and 360 degrees acquisition orbits on accuracy of cardiac function.

BACKGROUND: Quantitative blood pool single photon emission computed tomography (SPECT) (QBS) can measure ejection fraction (EF) and volumes from gated blood pool single photon emission tomography (GBPS) working in fully automatic mode in 3-dimensional space. The effects of 180 degrees and 360 degrees data acquisition in GBPS have not been fully evaluated. This study compares the accuracy of 360 degrees and 180 degrees data acquisition for left ventricular (LV) systolic function in a clinical study and measures LV volume by GBPS compared with ultrasound echocardiography. METHODS AND RESULTS: The study population comprised 9 normal volunteers and 34 patients. GBPS data were acquired by use of 360 degrees rotation and 60 stops per head. All 60 (360 degrees ) and 30 (45 degrees right anterior oblique to 45 degrees left posterior oblique) pieces of projection data that were selected for reconstructing the 180 degrees data were reconstructed and both ventricular functional parameters were automatically obtained by QBS software. The contour of the LV septal wall was concave in 6 patients (14%) when processed at 180 degrees , whereas a concave septum at 360 degrees processing was observed in only 1 patient (2%). The coefficients of correlation between 180 degrees and 360 degrees were 0.467 for the end-diastolic volume (EDV) and 0.648 for the end-systolic volume (ESV). The mean 180 degrees EDV value (152.9 +/- 46.1 mL) was significantly smaller than that of the 360 degrees EDV (191 +/- 70.8 mL) ( P < .001). However, there was no significant difference between the 360 degrees EDV (0.623) and 180 degrees EDV (0.407) as compared by echocardiography ( P = .218). The agreement of the EF between both methods was close ( r = 0.894, P < .0001). The agreement of the right ventricular volumes between the 180 degrees and 360 degrees orbits was close ( r = 0.800 for EDV and 0.706 for ESV). The EF was relatively dispersed between the 180 degrees and 360 degrees methods ( r = 0.642). CONCLUSION: This study showed that SPECT image acquisition by use of both the 180 degrees method and the 360 degrees method considerably underestimated LV volume quantification. In addition, the LV volume with the 180 degrees method was significantly smaller than that with the 360 degrees method. Thus a 360 degrees acquisition orbit may be suitable for more quantitatively accurate results when blood pool imaging is performed with gated SPECT.

Adult↗

PubMedDate not supplied

Quantitative analysis of cytokine mRNA expression in hearts from patients with nonischemic dilated cardiomyopathy (DCM).

PURPOSE AND METHODS: There is increasing evidence that inflammatory cytokines play an important role in the development of heart failure. To evaluate the role of cytokines in nonischemic DCM, we analyzed the relative quantity of cytokine mRNA expression in the hearts from DCM patients with refractory heart failure, using the ABI PRISM7700 real-time PCR system. We used heart tissues resected from 32 DCM patients at the time of elective partial ventriculectomy (PLV), and five biopsy specimens with normal histological findings as control. RESULTS AND DISCUSSION: Interleukin (IL)-1beta, IL-10, and Tumor Necrosis Factor (TNF)-alpha mRNA were expressed at low levels in all normal hearts. The number of IL-10-positive DCM cases was significantly smaller than normal controls (P = 0.0036). One (10%) of 10 DCM patients with IL-10 mRNA expression died after PLV, and 10 (45%) of 22 DCM patients without IL-10 mRNA expression died. IL-1beta mRNA was overexpressed (over twice the mean of control subjects) in 15 of 32, and TNF-alpha mRNA in 10 of 32 patients. We propose the classification of DCM patients into subgroups on the basis of cytokine mRNA expression. Anticytokine therapy or cytokine therapy may have potential in improving the condition of heart failure in certain subgroups of DCM patients. CONCLUSIONS: We suggest that DCM patients with heart failure deteriorate without IL-10 mRNA expression in the myocardium. The classification of DCM patients into subgroups on the basis of cytokine mRNA expression may have great value in considering the treatment of this heterogeneous disease state.

Adult↗

PubMedDate not supplied

Weekly variation of home and ambulatory blood pressure and relation between arterial stiffness and blood pressure measurements in community-dwelling hypertensives.

Although blood pressure (BP) is a major determinant of pulse wave velocity (PWV), some treatments have independent effects on BP and arterial stiffness. Although both ambulatory BP (ABP) and self-measured BP at home (HBP) have become important measures for the diagnosis and management of hypertension, single day recordings may be insufficient for a proper diagnosis of hypertension or the evaluation of treatment efficacy. To evaluate weekly variations in BP using 7-day HBP and 7-day ABP monitoring and to determine the relation between arterial stiffness and BP measurements in community-dwelling patients with hypertension. We enrolled 68 community-dwelling hypertensive subjects in this study. Significant weekly variations in systolic blood pressure (SBP) and diastolic blood pressure (DBP) were found in the awake ABP data (p < .01, respectively), while no significant weekly variations in the asleep ABP or the morning and evening HBP data were observed. In untreated subjects, significant correlations were obtained between the brachial-ankle PWV and the average awake SBP, the average asleep SBP and the average SBP measured by HBP in the evening. In treated subjects, only the average SBP measured by HBP in the morning was significantly correlated with the baPWV. Differences in the weekly variations in BP were observed between HBP and ABP monitoring. In addition, the morning systolic HBP was not correlated with arterial stiffness in untreated subjects with hypertension but was correlated in treated subjects. Relations between the morning HBP and arterial stiffness might be attributed to morning surges in BP and/or trough levels of antihypertensive drugs.

Blood Pressure Monitoring, Ambulatory↗