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Biomedical subjects

Yuichi Sato

Publications and source records attributed to Yuichi Sato.

At least 55 records · Page 3Linked to original sources
PubMed2006

Usefulness of rapid low-dose/high-dose 1-day 99mTc-sestamibi ECG-gated myocardial perfusion single-photon emission computed tomography.

BACKGROUND: The clinical usefulness of a rapid rest low-dose/stress high-dose (dose ratio =1:5) (99m)Tc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) protocol for the detection of coronary artery disease was evaluated. METHODS AND RESULTS: In 89 patients, rest images were obtained immediately after the injection of (99m)Tc-sestamibi (256.1+/-28.4 MBq) followed by drinking water (400 ml). Exercise or vasodilator stress test was performed immediately after the completion of rest imaging with the injection of (99m)Tc-sestamibi (1312.3 +/-167.6 MBq). Prior to the post-stress imaging, patients were asked again to drink water (400 ml) in order to eliminate subdiaphragmatic tracer activity. The myocardial count ratio (stress/rest) of (99m)Tc-sestamibi was calculated. Image quality was scored using a 4-point scale system (4= excellent, 3= good, 2= poor, 1= unacceptable). Coronary angiography was performed in 56 patients within 1 month of the SPECT scan. All patients successfully performed the protocol and total examination time was 108+/-7 min. The myocardial count ratio of (99m)Tc-sestamibi was always greater than 6. The image quality was satisfactory both at rest (3.4+/-0.9) and after stress (3.9+/-0.2). The sensitivity and specificity to detect coronary artery stenosis >50% was 84% and 97%, respectively. CONCLUSIONS: This rapid one-day (99m)Tc-sestamibi protocol provides adequate image quality and diagnostic accuracy for detecting coronary artery disease.

Adult↗
PubMed2006

Pure ventricular septal myocardial infarction in a young man with coronary artery ectasia.

The case of a 30-year-old man with myocardial infarction localized in the interventricular septum is described. Coronary angiography performed on day 28 after the onset of symptoms revealed ectasia in the right and left coronary arteries, but no overt stenotic or occlusive lesions were present. Spasm was induced in the first septal branch of the left anterior descending artery by an acetylcholine provocation test, and single photon emission computed tomography myocardial perfusion imaging showed a reduced thallium-201 uptake localized in the interventricular septum.

Adult↗
PubMed2006

Differential expression of N-cadherin and E-cadherin in normal human tissues.

E-cadherin, which expressed in various epithelial tissues, is important for the maintenance of normal epithelial phenotypes. However, the distribution of N-cadherin in normal human tissues has not been defined systemically. In the present study, we employed a sensitive, reliable immunohistochemical detection system for N-cadherin on formalin-fixed, paraffin-embedded tissue sections, and succeeded in demonstrating N- and E-cadherin protein expressions and their distribution in normal human tissues. E-cadherin immunoreactivity was detected in all the epithelial tissues examined, except for the adrenal cortical cells and granulosa cells. N-cadherin was selectively expressed on epithelial cells of the thymus, pituitary, pancreas, liver, adrenal, endometrium of the uterus, ovary, and stomach as well as in neuronal tissues. Double immunostaining revealed that N-cadherin expression was closely associated with the hormone-producing ability of cells in the pancreas and pituitary. Thus, this study indicated the possibility that N-cadherin is selectively expressed in relation to hormonal regulation in some organs and plays different functions in different situations. The method presented here should prove useful for the further investigation of the N-cadherin expression and function in several disease conditions on formalin-fixed, paraffin-embedded archival tissues.

Cadherins↗
PubMed2006

Control of the bioluminescence starting time by inoculated cell density.

In this study, we attempted to control the timing of light-emission from bioluminescent bacteria, by changed cell numbers inoculated into medium. Luminous bacteria express bioluminescence when the number of cells reached a threshold. Inoculated cell density had an effect on the time of bioluminescence starting. Samples were prepared by varying cell density of inoculation. In the results, all the vials showed different luminescence profiles in the order of inoculated cell population.

Animals↗
PubMed2006

[CT, MRI for diagnosis of acute coronary syndrome].

Recent pathological and clinical observations support the notion that coronary artery plaque disruption and subsequent thrombosis is the primary cause of acute coronary syndrome (ACS) including acute myocardial infarction and unstable angina. Therefore, detection and characterization of coronary artery plaques are of utmost importance in the management of patients with suspected coronary artery disease. Histologic and clinical observations using intravascular ultrasound have suggested that vulnerable, rupture-prone plaques are characterized by the presence of large lipid cores, thin fibrous caps and positive coronary artery remodeling. In this review, we describe the efficacy of multislice computed tomography (MSCT) to characterize vulnerable plaques, especially in patients with suspected ACS. In addition, the efficacy of coronary magnetic resonance imaging is discussed.

Angina, Unstable↗
PubMed2005

Cardioverter defibrillator implantation in an adult with isolated noncompaction of the ventricular myocardium.

Isolated noncompaction of the ventricular myocardium is an unclassified cardiomyopathy and is thought to be due to arrest of myocardial morphogenesis. Fatal ventricular arrhythmias may occur in approximately half of the patients and account for half of the death in this disorder. In this report, we describe a patient with isolated noncompaction of the ventricular myocardium in whom implantation of automatic cardioverter defibrillator was thought to be effective to prevent the risk of sudden cardiac death.

Defibrillators, Implantable↗
PubMed2005

Effect of pravastatin on malondialdehyde-modified low-density lipoprotein levels and coronary plaque regression as determined by three-dimensional intravascular ultrasound.

We hypothesized that a reduction in atherogenic malondialdehyde-modified low-density lipoprotein (MDA-LDL) levels, which may antagonize the action of atheroprotective high-density lipoprotein cholesterol, leads to coronary plaque regression. This study investigated the effects of pravastatin on the serum levels of MDA-LDL and coronary atherosclerosis. In a 6-month prospective study, 75 patients with stable coronary artery disease were randomly assigned to a pravastatin-treatment group (n = 52) or a control group (n = 23). Volumetric analyses were performed in matched coronary artery segments by 3-dimensional intravascular ultrasound. Pravastatin therapy for 6 months resulted in a decrease in coronary plaque volume (14.4%, p <0.0001) and a corresponding reduction in serum MDA-LDL levels (12.7%, p = 0.0001). In the pravastatin treatment group, the percentage of change in plaque volume correlated with changes in the MDA-LDL and high-density lipoprotein cholesterol levels (r = 0.52 and -0.55, respectively, p <0.0001) but not with the changes in any other lipid levels. Multivariate regression analysis revealed that a reduced MDA-LDL level is an independent predictor of plaque regression, as was an increase in high-density lipoprotein cholesterol. In conclusion, these results suggest that the reduction in the MDA-LDL levels induced by pravastatin may serve as a novel marker of coronary atherosclerosis regression.

Anticholesteremic Agents↗
PubMed2005

Assessment of coronary artery abnormalities by multislice spiral computed tomography in adolescents and young adults with Kawasaki disease.

Multislice spiral computed tomography was performed in 16 adolescents and young adults who had Kawasaki's disease to assess coronary artery abnormalities. Adequate images were obtained for 96% of major coronary segments. The sensitivity of multislice spiral computed tomography to detect coronary artery aneurysms was 100%, and that for significant stenoses and occlusions was 87.5%, whereas false-positive results due to severe calcification was present in 5 arteries and those due to cardiac motion artifact were present in 2, resulting in a specificity of 92.5%.

Adolescent↗
PubMed2005

Takotsubo-shaped cardiomyopathy with type I CD36 deficiency.

A transient left ventricular apical ballooning (so-called "ampulla" or "Takotsubo-shaped" cardiomyopathy) with type I CD36 deficiency is described in a 71-year-old woman. The patient was referred because of chest pain and worsening of dyspnea. Electrocardiogram showed T-wave inversions on the precordal leads, and acute coronary syndrome was suspected. Left ventricular apical ballooning was observed by echocardiogram and left ventriculography, and coronary arteriography did not reveal any significant stenosis. Left ventricular motion normalized at the follow-up period and there were no increases in specific markers for myocardial damage, such as myocardial band fraction of creatine kinase and troponin T, through out the admission. 123I-metaiodobengylguanidine myocardial single photon emission computed tomography (SPECT) revealed decreased accumulation areas at the apex, while 201Tl SPECT showed normal accumulation. An abnormal metabolism of cardiac free fatty acid was suggested by lack of accumulation of 123I beta-methyliodophenyl pentadecanoic acid (BMIPP) SPECT. No CD36 expression in either platelets or monocytes/macrophages was shown using flow cytometer analysis and type I CD36 deficiency was diagnosed. DNA sequencing showed that the patient had compound heterozygosity of the CD36 gene (a nucleotide change in C478T and an adenine insertion at nucleotide 1159 in exon 10). Although CD36 deficiency is thought to be involved with many cardiovascular disease and metabolic abnormalities, Takotsubo-shaped cardiomyopathy with CD36 deficiency had not been reported. Further studies of Takotsubo-shaped cardiomyopathy and CD36 deficiency may reveal an association between this cardiomyopathy and specific genetic profiles.

Aged↗
PubMed2005

Diagnosis of anomalous origin of the right coronary artery using multislice computed tomography: evaluation of possible causes of myocardial ischemia.

Anomalous origin of the right coronary artery (RCA) is a rare condition, but may cause myocardial ischemia and sudden death. Multislice computed tomography, which allows three-dimensional visualization of the coronary artery with high spatial resolution, may be the most promising imaging modality for diagnosing this anomaly. We describe a patient with anomalous origin of the RCA arising from the left sinus of Valsalva. Volume rendering, and axial and curved multiplanar images showed stenosis in the proximal portion of the RCA that coursed between the aorta and the pulmonary artery, and an acute angled take-off of the RCA from the aorta. Three-dimensional virtual angioscopic images showed a hypoplastic RCA orifice and luminal narrowing in the proximal portion of the RCA. Multislice computed tomography was thought to be useful for detecting anomalous origin of the RCA and for evaluating possible causes of myocardial ischemia.

Aged↗
PubMed2005

Efficacy of multislice computed tomography for the detection of acute coronary syndrome in the emergency department.

BACKGROUND: The diagnosis of acute coronary syndrome (ACS), especially non-ST-elevation myocardial infarction and unstable angina in the emergency department (ED) still remains a challenge. Multislice computed tomography (MSCT) allows assessment of not only coronary artery stenoses and occlusions, but also assessment of coronary artery plaques and myocardial perfusion status. METHODS AND RESULTS: MSCT was performed in 31 patients who were admitted to the ED because of chest pain persisting at least 30 min and non-diagnostic ECG changes and normal serum enzyme concentrations. Using MSCT, ACS was defined by coronary artery stenosis > or = 75% accompanied by computed tomography (CT)-low-density plaques, and/or by the presence of myocardial perfusion defects. ACS was confirmed by coronary stenosis > or = 75% by coronary angiography and/or subsequent elevation of troponin I concentration. In total, 22 patients were diagnosed as having ACS. MSCT detected stenoses with CT-low-density plaques in 21 and non-transmural myocardial perfusion defect in 3 patients. There was 1 false-positive and 1 false-negative result. The sensitivity and specificity of MSCT to identify ACS was 95.5% and 88.9%, respectively. CONCLUSION: MSCT provides diagnostic operating characteristics suitable for triage of patients with ACS in the ED.

Acute Disease↗
PubMed2005

Computed tomography assessment of the regression of an atherosclerotic coronary artery plaque.

Multislice spiral computed tomography (MSCT) permits the noninvasive visualization of coronary artery stenoses and occlusions, as well as atherosclerotic plaques, in patients with coronary artery disease. This report describes a patient with stable angina pectoris in whom the regression of the plaque and coronary artery remodeling was documented by serial MSCT.

Coronary Artery Disease↗
PubMed2005

Evaluation by multislice computed tomography of atherosclerotic coronary artery plaques in non-culprit, remote coronary arteries of patients with acute coronary syndrome.

BACKGROUND: Patients with acute coronary syndrome (ACS) frequently have vulnerable plaques in the remote coronary arteries, suggesting that ACS is part of the pan-coronary process. In the present study the computed tomography (CT) plaque density in non-culprit atherosclerotic coronary artery lesions was evaluated by multislice computed tomography (MSCT) in patients with ACS and non-ACS. METHODS AND RESULTS: MSCT was performed in 21 patients with ACS and 53 patients with non-ACS: 16 of the 21 ACS patients (76%) and 30 of the non-ACS 53 patients (57 %) had non-calcified plaques in the non-culprit coronary arteries (p=0.18). CT-low-density plaques (CT density <68 Hounsfield units (HU)) were more frequent in the ACS group (13/16 patients, 81%) than in the non-ACS group (13/30 patients, 43%, p=0.03). In addition, the CT density of the non-culprit lesion was significantly lower in patients with ACS than in those with non-ACS (44.1+/-22.9 and 77.3+/-33.7 HU, respectively). CONCLUSION: Patients with ACS more frequently had CT-low-density plaques in the non-culprit, remote arteries than those with non-ACS, which suggests that ACS treatment should focus not only on stabilizing the culprit lesion but also on systemic stabilization of non-culprit lesions.

Aged↗