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Biomedical subjects

Kazuhide Takeuchi

Publications and source records attributed to Kazuhide Takeuchi.

At least 55 records · Page 3Linked to original sources
PubMed2003

Prevalence of hepatitis C virus infection among patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is defined as inappropriate ventricular hypertrophy without a cardiac or systemic cause. On the other hand, hepatitis C virus (HCV) causes extrahepatic manifestations as well as chronic persistent infection in hepatocytes. We studied the association of HCV infection with HCM, comparing the prevalence of HCV antibodies between HCM patients and age- and gender-matched controls with other cardiovascular diseases at a single institution, for reasons of exclusion of bias. We then described the clinical features and genotype analysis of HCV RNA in HCM. The diagnosis of HCM was established by echocardiographic demonstration of a hypertrophied (> or =15 mm), nondilated left ventricle in the absence of another systemic or cardiovascular disease capable of producing the magnitude of hypertrophy observed. The study population consisted of 80 patients with HCM, in whom HCV antibody was examined (55 men and 25 women; mean age 56.6 +/- 12.4 years; ranging from 19 to 80 years), compared with a total of 80 age- and gender-matched controls without HCM. The prevalence of HCV infection in patients with HCM (18/80) was significantly higher than in control subjects (5/80) (Chi(2) = 7.312, P = 0.007). Of the 12 patients in whom the genotype of HCV was analyzed, 7 had type 1b and 5 had type 2a. The prevalence of HCV infection was higher in patients with HCM than in age- and gender-matched control subjects with other cardiovascular diseases. The result suggests that HCV may play an important role in these HCV-positive HCM patients.

Adult↗
PubMed2003

Beneficial effects of combination of ACE inhibitor and angiotensin II type 1 receptor blocker on cardiac remodeling in rat myocardial infarction.

OBJECTIVE: Angiotensin-converting enzyme (ACE) inhibitor and angiotensin II type I receptor blockers (ARB) prevent cardiac remodeling after myocardial infarction (MI). However, it is controversial whether combination therapy of ACE inhibitor and ARB is more effective on cardiac remodeling than each agent alone. In this study, we compared the effects of an ACE inhibitor (temocapril), an ARB (CS-866), and their combination on cardiac remodeling after MI. METHODS: Temocapril at 3 or 30 mg/kg/day, CS-866 at 1 or 10 mg/kg/day, or combined temocapril and CS-866 at 1.5 and 0.5 mg/kg/day or at 15 and 5 mg/kg/day, respectively, were administered to rats after MI. At 4 weeks after MI, we assessed hemodynamics, cardiac function by Doppler echocardiography and non-infarcted myocardial mRNA expression. RESULTS: Animals treated with a combination of the two drugs had hemodynamics, heart weights and dimensions similar to the other treated animals. However, the combination of the two drugs suppressed ANP, BNP and other gene expressions related to contractile proteins of fetal type and collagens more effectively than ACE inhibitor or ARB alone. CONCLUSION: These data suggest that combination of the two drugs, independent of the hemodynamic effect, may improve left ventricular phenotypic change, collagen accumulation and diastolic function.

Angiotensin II↗
PubMed2003

Automated quantification of left ventricular function by the automated contour tracking method.

The automated contour tracking (ACT) method has been developed for the automated measurement of area volume using the energy minimization method without tracing a region of interest. The purpose of this study was to compare the ACT method and left ventriculography (LVG) for the measurement of left ventricular (LV) function in the clinical setting. An apical four-chamber view was visualized by two-dimensional echocardiography and recorded for off-line analysis in 14 patients with high-quality images who underwent LVG. The ACT method automatically traces the endocardial border from the recorded images and calculates LV volumes (end-diastole and end-systole) and ejection fraction (EF). Both ACT and LVG were compared by linear regression analysis for the measurement of EF. EF determined by the ACT method agreed well with that by LVG (r = 0.96, y = 0.94x + 4.6, standard error of the estimate = 3.9%). The mean difference between the ACT and LVG was -1.4%+/- 7.3%. In conclusion, the ACT method is reliable for noninvasive estimation of EF in high-quality images. This suggests that this new technique may be useful in the automated quantification of LV function.

Adult↗
PubMed2003

Physiologic assessment of left anterior descending coronary artery stenosis by quantitative intravenous myocardial contrast echocardiography in humans: comparison with exercise single-photon emission computed tomography.

OBJECTIVE: To clarify the potential of quantitative intravenous myocardial contrast echocardiography (MCE) for physiologic assessment of the left anterior descending artery (LAD) stenosis. METHODS: We studied 38 patients with suspected coronary artery disease. MCE was performed by continuous infusion of Levovist and intermittent ultrasonic exposure. Images were obtained from the apical four-chamber view at rest and after dipyridamole infusion. The background-subtracted intensity versus pulsing interval plots were fitted to an exponential function,Y=A(1 e-ss), to obtain the plateau level (A) and rate of rise (ss) of background-subtracted intensity both at rest and after dipyridamole infusion. We compared the results with those of exercise thallium-201 single-photon emission computed tomography (SPECT). RESULTS: Of the 38 patients, 18 patients exhibited redistribution in the LAD territories with SPECT (group A), although 20 did not (group B). The ss reserve (DIP/rest) in group A was significantly lower than those in group B (0.8 +/- 0.5 versus 2.0 +/- 1.1, P < 0.001), while the A reserve did not differ between the two groups (1.2 +/- 0.6 versus 1.0 +/- 0.5, P = NS). The ss reserve <1.1, which was the optimal cutoff value, provided sensitivity of 79% and specificity of 84% for the presence of redistribution in SPECT. CONCLUSIONS: Quantitative intravenous MCE allows us to estimate physiologic severity of the LAD stenosis in the clinical setting.

Contrast Media↗
PubMed2003

Rapid and accurate noninvasive assessment of global left ventricular systolic function using biplane advanced automated contour tracking method.

BACKGROUND: The advanced automated contour tracking (AACT) method has been newly developed for automated detection of the left ventricular endocardial boundary. Left ventricular ejection fraction (LVEF) may be estimated by applying the AACT method to 2 orthogonal planes of patients even when regional wall-motion abnormalities exist. The purpose of this study was to examine the reliability of the biplane AACT method in the measurement of LVEF in patients with suggested ischemic heart disease with use of quantitative gated single photon emission computed tomography (QGS) as a reference standard. METHODS: The study population consisted of 47 consecutive patients with suggested ischemic heart disease. All patients underwent 2-dimensional echocardiography and QGS. Biplane LVEF from apical 4- and 2-chamber views was measured offline by the AACT method using disk summation method. The accuracy of the AACT method for LVEF measurement was determined in comparison with QGS. RESULTS: In 41 (29 with and 12 without regional wall-motion abnormalities) of 47 patients (87%), automated tracing of the endocardial border was adequately achieved with the AACT method. LVEF measured by the AACT method correlated well with that measured by QGS (y = 0.97x +2.4, r = 0.91). The mean difference between AACT and QGS was 0.6 +/- 5.5% (mean +/- SD). The mean time required for analysis of 1 set of images during 1 cardiac cycle by the AACT method was much shorter than that required by manual tracing method (7 +/- 1 vs 37 +/- 4 seconds, P <.0001). CONCLUSION: The biplane AACT method provides accurate and quick measurement of LVEF in patients even with regional wall-motion abnormalities.

Adult↗
PubMed2003

Observation of the ischemic cascade in humans using contrast echocardiography during dobutamine stress.

Experimental studies have postulated the ischemic cascade and the present study was designed to elucidate whether it can be observed in the clinical setting. Fifty-three patients suspected of having coronary artery disease were studied. Myocardial perfusion abnormalities (MPA) and wall motion abnormalities (WMA) were assessed simultaneously by infusion of Levovist during dobutamine stress echocardiography. Time - intensity data of myocardial opacification were fitted for Y=A (1-e(-)(beta) (t)) from which the rate of increase (beta) of intensity were derived both at rest and during stress. Wall motion was also given a score. Bright opacification was observed in 50 patients: 25 showed significant stenosis (>50%) in the left anterior descending artery (group II) on coronary angiography and 25 did not (group I). Significant differences were found in the beta ratio (stress/rest) between the 2 groups at a low-dose (2.0+/-0.3 vs 1.5+/-0.5, p<0.05) and at a high-dose of dobutamine (2.7+/-1.0 vs 1.1+/-0.5, p<0.001), whereas the wall motion score differed only at a high-dose. Of the 25 patients in group II, MPA preceded WMA in 12, both occurred at the same stage in 12, and neither MPA nor WMA was seen in 1. These data prove the ischemic cascade clinically, using contrast echocardiography, by demonstrating that MPA precede WMA during dobutamine stress in patients with coronary stenosis.

Adrenergic beta-Agonists↗
PubMed2003

Impact of diabetes mellitus on worsening of the left ventricular ejection fraction in exercise-gated 201Tl myocardial single photon emission computed tomography in patients with coronary artery disease.

It remains uncertain whether factors other than the severity of coronary artery disease (CAD) are associated with the worsening of the left ventricular ejection fraction (LVEF) by exercise. In the present study the impact of coronary risk factors on the worsening of LVEF by exercise was investigated in 391 patients with known or suspected CAD using exercise-gated (201)Tl scanning to calculate the LVEF. Significant worsening of the LVEF by exercise was defined as >4.7% (mean plus 1 SD of the value in 116 patients without CAD). Multivariate analysis revealed that diabetes mellitus (DM) was an independent risk factor for the worsening of LVEF by exercise in patients with multivessel (2- or 3-vessel) CAD with an odds ratio (95% confidence interval) of 2.2 (1.1-4.5, p=0.037). In 157 patients with 2- or 3-vessel CAD, 20 (23.5%) of 85 nondiabetic patients and 31 (43.1%, p=0.009 vs nondiabetic patients) of 72 diabetic patients showed significant worsening of LVEF by exercise. In patients with 2- or 3-vessel CAD, there was no significant difference in Gensini score or reversibility of perfusion defects between nondiabetic and diabetic patients. Thus, DM is a risk factor for worsening LVEF by exercise in addition to the severity of CAD.

Adult↗
PubMed2003

Identification of cardiac sarcoidosis with (13)N-NH(3)/(18)F-FDG PET.

UNLABELLED: To our knowledge, no study investigating the usefulness of cardiac PET for detection of myocardial involvement of sarcoidosis is available. We investigated whether (13)N-NH(3)/(18)F-FDG PET could identify cardiac involvement in patients with sarcoidosis. METHODS: Seventeen patients with cardiac sarcoidosis underwent cardiac (13)N-NH(3)/(18)F-FDG PET under fasting condition. Systemic sarcoidosis was diagnosed by histologically proven noncaseating epithelioid granuloma, and cardiac sarcoidosis was diagnosed according to the Japanese Ministry of Health and Welfare guidelines for diagnosing cardiac sarcoidosis. RESULTS: Only 6 patients exhibited myocardial (201)Tl defects and only 3 patients exhibited abnormal (67)Ga accumulation in the heart. Thirteen patients exhibited (13)N-NH(3) defects, and 14 patients exhibited increased (18)F-FDG uptake in the heart; 12 patients exhibited both (13)N-NH(3) defects and increased (18)F-FDG uptake, 2 patients exhibited increased (18)F-FDG uptake but no (13)N-NH(3) defect, and 1 patient exhibited (13)N-NH(3) defects but no increased (18)F-FDG uptake. (13)N-NH(3) defects were observed frequently in the basal anteroseptal wall of the left ventricle, and increased (18)F-FDG uptake was observed frequently in the basal and midanteroseptal-lateral wall of the left ventricle. Involvement of the apex was rare. Seven patients were treated with steroid hormone and underwent follow-up cardiac PET 1 mo after steroid therapy. (13)N-NH(3) defects exhibited no significant change after steroid therapy, whereas increased (18)F-FDG uptake was markedly diminished in size and intensity in 5 patients and disappeared completely in 2 patients. CONCLUSION: Our findings suggest that cardiac (13)N-NH(3)/(18)F-FDG PET is the most useful method both for the identification of cardiac involvement of sarcoidosis and for the assessment of cardiac sarcoidosis disease activity.

Adult↗
PubMed2002

Neutrophil infiltration of culprit lesions in acute coronary syndromes.

BACKGROUND: Neutrophils in unstable atherosclerotic lesions have not received much consideration, despite accumulating evidence suggesting a link between systemic inflammation and acute coronary syndromes. METHODS AND RESULTS: Coronary artery segments were obtained at autopsy from 13 patients with acute myocardial infarction (AMI); 8 had a ruptured and 5 an eroded plaque. Patients (n=45) who had died of noncardiovascular diseases served as reference. Atherectomy specimens were obtained from 35 patients with stable angina pectoris (SAP) and from 32 patients with unstable angina pectoris (UAP). Antibodies against CD66b, elastase, myeloperoxidase, and CD11b identified neutrophils; CD10 identified neutral endopeptidase (NEP). CD66b-positive and NEP-positive neutrophils were counted and expressed as a number per square millimeter of tissue. All specimens with plaque rupture or erosion showed distinct neutrophil infiltration; the number did not differ between ruptured and eroded plaques. However, the number of NEP-positive neutrophils was significantly higher (P<0.0001) in ruptured plaques than in eroded plaques. UAP patients showed neutrophils in 14 of 32 culprit lesions; in SAP only 2 of 35 lesions contained neutrophils. The number of neutrophils and NEP-positive cells in patients with UAP was significantly higher (neutrophils, P<0.0005; NEP-positive cells, P<0.005) than in patients with SAP. CONCLUSIONS: The observations suggest that neutrophil infiltration is actively associated with acute coronary events. The high number of NEP-positive neutrophils in ruptured plaques, compared with eroded plaques, may reflect differences in the underlying pathophysiological mechanisms.

Acute Disease↗
PubMed2002

Short- and long-term outcomes of compromised side branches after Multi-Link stent implantation.

The Multi-Link stent is superior to other stents in terms of low rates of restenosis and target vessel revascularization. However, few data exist regarding short- and long-term outcomes for side branches after stenting. We evaluated short and long clinical outcomes and angiographic predictors of side-branch occlusion after the deployment of 137 Multi-Link stents. Thirty-four (25%) of the 137 side branches occluded immediately after stenting. We attempted reangioplasty for the side branches and our success rate was 85%. The incidence of side branches with intrinsic ostial disease was more than 50% before stenting and origination from the stented midsegment was a powerful angiographic predictor of side-branch occlusion. Side-branch patency is well maintained long-term. The incidence of restenosis within and near the stented segment of the parent vessel was 19%, and the incidence of target vessel revascularization was 15%. We recommend the use of Multi-Link stents regardless of the presence of side branches in the vicinity of the stenosis.

Aged↗
PubMed2002

Giant aneurysm of the membranous ventricular septum extending outside the heart: diagnosis by transthoracic color flow Doppler echocardiography.

Aneurysm of the membranous ventricular septum (AMS) is a congenital cardiac anomaly often associated with ventricular septal defect. This aneurysm usually pouches into the right side of the heart and remains intracardiac. An AMS that extends outside of the heart is rare. We report an unusual case of a giant extracardiac AMS diagnosed by transthoracic color flow Doppler echocardiography.

Cardiac Catheterization↗
PubMed2002

Pitfalls of echocardiographic measurement in tissue harmonic imaging: in vitro and in vivo study.

BACKGROUND: Tissue harmonic imaging (THI) is a useful method for endocardial border detection by transthoracic echocardiography, especially in technically difficult patients, even though accuracy of this method in the echocardiographic measurement is unclear. The purpose of this study is to evaluate the accuracy of echocardiographic measurement by THI in vivo and in vitro. METHODS: In vitro, we measured wall thickness, dimension, and volume of the excised hearts by THI. In 11 patients, we assessed the comparative accuracy of THI and fundamental imaging (FI) in determination of left ventricular (LV) wall thickness, dimension, volume, and ejection fraction. RESULTS: In vitro, thickness measurements by THI overestimated true length, and both volume and dimension measurements by THI underestimated true values. In vivo, LV ejection fraction measurements obtained by THI exhibited excellent correlation and agreement with those obtained by FI. However, LV wall thickness determined by THI was significantly larger than that determined by FI, and the dimensions and volume of LV measured by THI were significantly smaller than those measured by FI. CONCLUSION: Although THI is an excellent imaging technique for determination of LV ejection fraction, echocardiographic measurement by THI underestimates LV dimensions and volume, and overestimates LV wall thickness.

Aged↗
PubMed2002

Dominant negative mutant of c-Jun inhibits cardiomyocyte hypertrophy induced by endothelin 1 and phenylephrine.

The activator protein 1 (AP-1) transcriptional complex, containing Jun and Fos proteins, is involved in regulating many cellular processes such as proliferation and differentiation. However, little is known about a direct relationship between AP-1 activities and cardiomyocyte hypertrophy. To elucidate the roles of myocardial AP-1 activities, dominant negative mutant of c-Jun (DNJun) was overexpressed in cultured rat neonatal ventricular myocytes by adenovirus vector to abrogate endogenous AP-1 activation. Cardiomyocytes were treated with 100 nmol/L endothelin 1 (ET) and 10 micromol/L phenylephrine (PE) to induce myocardial cell hypertrophy. Both ET and PE significantly enhanced AP-1 DNA binding activities (3.4-fold by ET and 4.8-fold by PE at 3 hours, P<0.01). At 48 hours after stimulation, ET and PE significantly increased incorporation of (3)H-phenylalanine (1.4-fold by ET and 1.5-fold by PE, P<0.01), cell size (2.3-fold and 2.5-fold, P<0.01), and mRNA expression of atrial natriuretic peptide (ANP; 1.9-fold and 1.8-fold, P<0.01) and brain natriuretic peptide (BNP; 1.6-fold and 1.6-fold, P<0.01). Adenovirus carrying DNJun prevented the transcriptional activation of the AP-1 by ET and PE, using AP-1 reporter enzyme firefly luciferase assay. Moreover, DNJun prevented the increase in incorporation of (3)H-phenylalanine, cell size, and the mRNA expression of ANP and BNP by ET and PE. In conclusion, we provide the first evidence that DNJun inhibits cardiomyocyte hypertrophy through inhibition of AP-1 transcriptional activity.

Adenoviridae↗
PubMed2002

Unruptured aneurysm of the sinus of valsalva with Behçet's disease.

A 52-year-old Japanese man who had suffered from Behçet's disease since the age of 45 years was admitted to hospital for evaluation of syncope and heart murmur. Echocardiography and aortography revealed severe aortic regurgitation and cystic masses under the right coronary cusp and the left ventricular outflow tract, but no shunt jet. He was diagnosed with unruptured aneurysm of the sinus of Valsalva, and surgical closure of the orifice of the aneurysm was performed. The diameter of the orifice was 11 mm and the aneurysm was 15 mm in depth, and consisted of 2 chambers. Because the aortic regurgitation was reduced after patch closure of the orifice, aortic valve replacement was not performed. Unruptured aneurysm of the sinus of Valsalva is a rare clinical lesion, but patients with active inflammatory disease of the aorta, such as in Behçet's disease, should have periodic echocardiography for early detection of an aneurysm or valvular involvement, even if there are not any symptoms.

Aortic Aneurysm↗
PubMed2002

Transmitral inflow pattern assessed by Doppler echocardiography in angiotensin II type 1A receptor knockout mice with myocardial infarction.

Many studies have suggested that the renin-angiotensin system plays an important role in the left ventricular (LV) remodeling and cardiac dysfunction that occurs after myocardial infarction (MI). Although angiotensin II type IA (AT1A) receptor knockout (KO) mice are reported to display less LV remodeling after MI, diastolic dysfunction has not been fully evaluated, so the present study measured transmitral inflow pattern in both AT1A receptor KO mice with MI (KO-MI) and wild type mice with MI (WT-MI). Cardiac geometry and function were examined by Doppler echocardiography and myocardial mRNA expression was determined by Northern blot analysis at 4 weeks after MI. The LV internal diastolic dimension of WT-MI was larger than that of the KO-MI (p<0.05). Marked increases in the E wave velocity and the ratio of the peak velocity of the E wave to the A wave were observed in the WT-MI (p<0.01). The deceleration rate of the E wave in KO-MI was lower than in WT-MI (p<0.05). mRNA expressions of ANP, BNP, collagen I and collagen III in the non-infarcted LV and RV of KO-MI were significantly lower than WT-MI. In conclusion, transmitral inflow abnormalities in KO-MI were attenuated compared with WT-MI.

Animals↗
PubMed2002

Hepatocyte growth factor production may be related to the inflammatory response in patients with acute myocardial infarction.

Hepatocyte growth factor (HGF) is a well-known powerful proliferative factor of vascular endothelial cells and it has been reported that plasma HGF concentrations are increased in acute myocardial infarction (AMI), although the mechanisms are not yet well delineated. Serum HGF levels and C-reactive protein (CRP) were measured in 22 patients with unstable angina pectoris (UAP) (15 males, 7 females; class IIb or IIIb of the Braunwald classification), 60 patients with AMI (37 males, 23 females; average time from the onset of symptoms to admission 4.6+/-0.7h, range, 0.5-12h), and 20 normal subjects. Immediate angioplasties were performed in 51 patients with AMI, and the time course of the HGF levels were measured in 31 patients among them. Heparin dramatically increased the HGF level and it declined to the normal range 18h after heparin injection. Blood samples were taken before heparin treatment, or at least 24h after. Serum HGF levels on admission was significantly increased in UAP (mean+/-SE: 0.30+/-0.03ng/ml, p<0.01), and AMI (0.27+/-0.02ng/ml, p<0.01) compared with the normal subjects (0.19+/-0.01 ng/ml). Even in the early stage (within 3 h of onset of symptoms to admission, average time was 1.8+/-0.1 h), serum HGF levels were already elevated (0.25+/-0.02 ng/ml, p<0.05). There was no significant difference between the HGF levels in UAP and AMI. Fifty-one of the 60 patients with AMI underwent immediate percutaneous transluminal coronary angioplasty and blood samples were obtained from 31 of them on days 7, 14, and 21 after MI. Serum HGF levels peaked on day 7 (0.34+/-0.04ng/ml, p<0.01) and there was a weak relationship between peak creatine kinase and serum HGF levels at that time. A statistically significant correlation was found between peak CRP and serum HGF levels on day 7 (r=0.62: p<0.001). Serum HGF levels decreased to nearly normal by day 21 (0.22+/-0.01 ng/ml). The study shows that serum HGF levels during the early stage of AMI increased significantly and peaked by day 7 after the onset, at which time there was a strong correlation with peak CRP levels. These data suggest that HGF production may be related to the inflammatory response in AMI.

Aged↗