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Biomedical subjects

Junichi Yoshikawa

Publications and source records attributed to Junichi Yoshikawa.

At least 19 recordsLinked to original sources
PubMed2004

Effect of azithromycin therapy on coronary circulation in patients with coronary artery disease.

This study examined the effect of azithromycin therapy on the coronary microcirculation using measurement of coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography in 35 patients with coronary artery disease. CFVR increased significantly after azithromycin therapy (3.0 +/- 0.7 vs 3.5 +/- 0.7, p <0.001). The changes in CFVR were negatively correlated with changes in high-sensitivity C-reactive protein levels in patients receiving azithromycin.

Aged↗
PubMed2004

Clinical significance of von Willebrand factor in patients with adult dermatomyositis.

Because the clinical significance of von Willebrand factor (vWF), a marker of endothelial injury, has not been well studied in adult patients with dermatomyositis (DM), we evaluated whether plasma vWF levels are useful as an index of disease activity in these patients. We measured plasma vWF antigen levels in 11 patients with active adult DM, 13 patients with inactive DM, and 18 healthy subjects using an enzyme-linked immunosorbent assay. The association of vWF level with clinical condition and muscle-derived enzyme leakage among DM patients was examined using analysis of covariance and logistic regression analysis. Furthermore, we studied the effects of treatment on the vWF antigen level. The mean vWF antigen level was significantly higher in active DM patients than in inactive DM patients and healthy subjects. Higher vWF levels were associated with clinical symptoms, such as general fatigue, fever, and muscle weakness. They were also associated with the levels of aspartate aminotransferase, alanine aminotransferase, and aldolase, but not with those of lactate dehydrogenase and creatine kinase (CK). vWF antigen was correlated with muscle enzymes except for CK. The plasma vWF levels in six patients with active DM significantly decreased after successful corticosteroid treatment. Plasma vWF level may be considered a useful marker of disease activity in adult DM patients.

Adolescent↗
PubMed2004

Spotty calcification typifies the culprit plaque in patients with acute myocardial infarction: an intravascular ultrasound study.

BACKGROUND: Calcification is a common finding in human coronary arteries; however, the relationship between calcification patterns, plaque morphology, and patterns of remodeling of culprit lesions in a comparison of patients with acute coronary syndromes (ACS) and those with stable conditions has not been documented. METHODS AND RESULTS: Preinterventional intravascular ultrasound (IVUS) images of 178 patients were studied, 61 with acute myocardial infarction (AMI), 70 with unstable angina pectoris (UAP), and 47 with stable angina pectoris (SAP). The frequency of calcium deposits within an arc of less than 90 degrees for all calcium deposits was significantly different in culprit lesions of patients with AMI, UAP, and SAP (P<0.0001). Moreover, the average number of calcium deposits within an arc of <90 degrees per patient was significantly higher in AMI than in SAP (P<0.0005; mean+/-SD, AMI 1.4+/-1.3, SAP 0.5+/-0.8). Conversely, calcium deposits were significantly longer in SAP patients (P<0.0001; mean+/-SD, AMI 2.2+/-1.6, UAP 1.9+/-1.8, and SAP 4.3+/-3.2 mm). In AMI patients, the typical pattern was spotty calcification, associated with a fibrofatty plaque and positive remodeling. In ACS patients showing negative remodeling, no calcification was the most frequent observation. Conversely, SAP patients had the highest frequency of extensive calcification. CONCLUSIONS: Our observations show that IVUS allows the identification of vulnerable plaques in coronary arteries, not only by identifying a fibrofatty plaque and positive remodeling, but also by identifying a spotty pattern of calcification.

Aged↗
PubMed2004

Accuracy of measurement of left ventricular volume and ejection fraction by new real-time three-dimensional echocardiography in patients with wall motion abnormalities secondary to myocardial infarction.

Three-dimensional echocardiography is an ideal tool for the measurement of left ventricular (LV) volume because no geometric assumptions about LV shape are needed. The introduction of new real-time 3-dimensional echocardiography (RT3DE) has allowed rapid acquisition of a 3-dimensional dataset with good image quality. The purpose of this study was to examine the accuracy of RT3DE for the measurement of LV volume and ejection fraction in patients with wall motion abnormalities by using quantitative gated single-photon emission computed tomography (QGSPECT) as a reference standard. The study population consisted of 25 consecutive patients with wall motion abnormalities who underwent LV volume measurement by 2-dimensional echocardiography and by QGSPECT. LV volume and ejection fraction by RT3DE were measured offline by using the average rotation method. In 23 of 25 patients (92%), it was possible to measure 3-dimensional volume with RT3DE. RT3DE correlated well with QGSPECT in the measurement of end-diastolic volume and end-systolic volume (r = 0.97, mean difference 3.4 ml; r = 0.98, mean difference 2.0 ml, respectively), 2-dimensional echocardiography also correlated with QGSPECT but underestimated LV volume (r = 0.98, mean difference 21.1 ml; r = 0.98, mean difference 15.6 ml, respectively). Ejection fraction obtained by RT3DE had better agreement with that obtained by QGSPECT than that obtained by 2-dimensional echocardiography (r = 0.92, mean difference -0.2%; r = 0.89, mean difference -2.7%, respectively). RT3DE allows convenient and accurate estimation of LV volume and ejection fraction in patients with wall motion abnormalities.

Adult↗
PubMed2004

The decrease of plaque volume during percutaneous coronary intervention has a negative impact on coronary flow in acute myocardial infarction: a major role of percutaneous coronary intervention-induced embolization.

OBJECTIVES: The aim of this study was to evaluate how decreased plaque volume during percutaneous coronary intervention (PCI) affects coronary flow in patients with acute myocardial infarction (AMI). BACKGROUND: Coronary flow after reperfusion therapy is a major determinant of clinical outcomes in patients with AMI. However, little is still known about the changes in coronary flow that appear after PCI in response to the decreased plaque during the procedure. METHODS: The study group comprised 60 patients with AMI who underwent pre- and post-PCI intravascular ultrasound (IVUS). Qualitative and quantitative analyses were performed on all IVUS procedures. External elastic membrane volume (EEMV), lumen volume (LV), and plaque volume (PV) were measured every 1.0 mm to include the lesion and reference segments 3.0 mm proximal and distal to the lesion. The difference between pre- and post-PCI PV was defined as the index of the decrease in plaque volume (DeltaPV). The corrected TIMI frame count (CTFC) was used to evaluate coronary flow after PCI. RESULTS: Plaque volume was decreased at post-PCI IVUS in all 60 patients. Inadequate reflow (CTFC >40) was observed in 13 patients (21.7%). The decrease in PV was significantly larger in patients with inadequate reflow than in those with reflow (49.4 +/- 18.9 vs. 31.7 +/- 15.5 mm(3), p = 0.0010). Also, DeltaPV was significantly correlated with CTFC after PCI (r = 0.415, p = 0.0012). CONCLUSIONS: The decrease in PV during PCI has a negative impact on coronary flow after PCI in patients with AMI. Embolization induced by PCI may occur in all patients with AMI.

Angioplasty, Balloon, Coronary↗
PubMed2004

Comparative effects of valsartan versus amlodipine on left ventricular mass and reactive oxygen species formation by monocytes in hypertensive patients with left ventricular hypertrophy.

OBJECTIVES: To compare the effects of the angiotensin receptor blocker (ARB) valsartan versus the calcium channel blocker amlodipine, reactive oxygen species (ROS) formation by monocytes, C-reactive protein (CRP), and left ventricular (LV) mass were studied in 104 hypertensive patients with left ventricular hypertrophy (LVH). BACKGROUND: There is evidence that ARBs have blood pressure (BP)-independent effects on LV mass. Whether regression of LV mass by ARBs is correlated to ROS formation by monocytes and CRP is not fully understood yet. METHODS: A cross-sectional and prospective study was performed. Participants were randomly assigned to either the 80-mg valsartan (n = 52) or 5-mg amlodipine (n = 52) group and were treated for eight months. The left ventricular mass index (LVMI) was calculated from two-dimensional M-mode echocardiography. Formation of ROS by monocytes was measured by gated flow cytometry. In addition, CRP, plasma renin activity, plasma aldosterone, and traditional risk factors were assessed. RESULTS: Multiple regression analysis showed a significant correlation between LVMI and ROS formation by monocytes and between LVMI and CRP. Treatment reduced BP to a similar extent in both groups. Valsartan significantly reduced LVMI after eight months, but amlodipine had less effect (16% vs. 1.2%, n = 50, p < 0.01). Formation of ROS by monocytes was reduced to a greater extent with valsartan than with amlodipine (28% vs. 2%, n = 50, p < 0.01). Valsartan but not amlodipine reduced CRP levels. A significant correlation between changes in ROS formation by monocytes and LVMI or between CRP and LVMI was observed. CONCLUSIONS: The ARB valsartan has BP-independent effects on LVH, ROS formation by monocytes, and CRP in hypertensive patients with LVH.

Amlodipine↗
PubMed2004

Black tea increases coronary flow velocity reserve in healthy male subjects.

Epidemiologic studies suggest that tea consumption decreases the risk for cardiovascular events. However, there has been no clinical report examining the effects of tea consumption on coronary circulation. The purpose of this study was to evaluate the effects of black tea on coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography (TTDE). This was a double-blind crossover study of 10 healthy male volunteers conducted to compare the effects of black tea and caffeine on coronary circulation. The coronary flow velocity of the left anterior descending coronary artery was measured at baseline and at hyperemia during adenosine triphosphate infusion by TTDE to determine CFVR. The CFVR ratio was defined as the ratio of CFVR after beverage consumption to CFVR before beverage consumption. All data were divided into 2 groups according to beverage type: group T (black tea) and group C (caffeine). Two-way analysis of variance showed a significant group effect and interaction in CFVR before and after beverage consumption (p = 0.001). CFVR significantly increased after tea consumption in group T (4.5 +/- 0.9 vs 5.2 +/- 0.9, p <0.0001). The CFVR ratio of group T was larger than that of group C (1.18 +/- 0.07 vs 1.04 +/- 0.08, p = 0.002). Acute black tea consumption improves coronary vessel function, as determined by CFVR.

Adult↗
PubMed2004

Accelerated decline in lung function and impaired reversibility with salbutamol in asthmatic patients with chronic hepatitis C virus infection: a 6-year follow-up study.

PURPOSE: Chronic hepatitis C virus (HCV) infection may have adverse effects on pulmonary function in patients with chronic obstructive pulmonary disease. This prospective study was designed to determine whether chronic HCV infection affects decline in lung function and airway responses to salbutamol in asthmatic patients. METHODS: Interferon alpha (6 MIU three times a week for 6 months) was given to 55 HCV-positive asthmatic patients, 18 of whom had a virologic response to interferon. Pre- and postbronchodilator forced expiratory volume in 1 second (FEV(1)) and reversibility with salbutamol or oxitropium at years 1, 3, and 6 after interferon therapy were examined. RESULTS: We found a significant decrease in pre- and postbronchodilator FEV(1) from year 1 to years 3 and 6 only in interferon nonresponders. Reversibility with salbutamol at years 3 and 6 was significantly lower in interferon nonresponders than in HCV-negative patients (P <0.0001) and interferon responders (P <0.0001). Moreover, there was a steep decline in reversibility with salbutamol during the follow-up period only in interferon nonresponders. In contrast, reversibility with oxitropium at years 3 and 6 was significantly higher in interferon nonresponders than in HCV-negative patients and interferon responders, and there was a steep increase in reversibility with oxitropium only in interferon nonresponders. In addition, declines in the diffusing capacity of the lung for carbon monoxide during follow-up were significantly greater in interferon nonresponders than in HCV-negative patients and interferon responders. CONCLUSION: Chronic HCV infection is associated with an accelerated decline in lung function and impaired reversibility with salbutamol among asthmatic patients who do not respond to interferon therapy.

Albuterol↗
PubMed2004

Intravenous nicorandil can reduce the occurrence of ventricular fibrillation and QT dispersion in patients with successful coronary angioplasty in acute myocardial infarction.

BACKGROUND: Because nicorandil, a potassium channel opener, has a cardioprotective effect and attenuates reperfusion injury in patients with acute myocardial infarction (AMI), intravenous nicorandil should reduce arrhythmic mortality and QT dispersion in patients with AMI. OBJECTIVES: The purpose of this study was to evaluate whether intravenous nicorandil reduces the occurrence of ventricular fibrillation and QT dispersion in patients with successful coronary angioplasty in AMI. METHODS: A historical cohort study on the effect of nicorandil on ventricular fibrillation and QT dispersion was conducted. Eighty-three patients with AMI who underwent successful percutaneous transluminal coronary angioplasty (PTCA) were enrolled. The patients were divided into two groups: nicorandil (n=46) and control group (n=37). Nicorandil was injected at 4 mg/h continuously from admission to 48 h after PTCA in the nicorandil group. QT dispersion was measured before, immediately after, 24 h after and 48 h after PTCA. RESULTS: Ventricular fibrillation was observed in three patients in the control group, but none was observed in the nicorandil group. QT dispersion in the nicorandil group was shorter than that in the control group 48 h after PTCA (QT dispersion was 23.2+/-16.1 ms and 33.4+/-24.0 ms, respectively, P<0.05). There was a significant difference between the two groups in time course after the onset of AMI (P<0.05). CONCLUSIONS: Because intravenous nicorandil reduces the occurrence of ventricular fibrillation and QT dispersion in patients with successful coronary angioplasty in AMI, it would prevent the occurrence of cardiac events after successful PTCA for AMI.

Angioplasty, Balloon, Coronary↗
PubMed2004

Effects of carvedilol on oxidative stress in polymorphonuclear and mononuclear cells in patients with essential hypertension.

PURPOSE: To compare the effects of carvedilol and propranolol on oxidative stress in leukocytes and C-reactive protein levels in patients with hypertension. METHODS: Sixty hypertensive patients were randomly assigned to carvedilol (20 mg; n = 30) or propranolol (60 mg; n = 30) for 6 months. Thirty normotensive subjects who were given placebo served as controls. Oxidative stress in polymorphonuclear cells and mononuclear cells were measured by gated flow cytometry. C-reactive protein levels were measured by immunonephelometric assay. RESULTS: Oxidative stress in polymorphonuclear cells and mononuclear cells was increased significantly in hypertensive patients compared with in normotensive controls. After 6 months of treatment, carvedilol decreased oxidative stress significantly in polymorphonuclear cells by a mean of 45 arbitrary units (95% confidence interval [CI]: 32 to 59 arbitrary units; P <0.001) and propranolol decreased oxidative stress significantly by 20 arbitrary units (95% CI: 7 to 33 arbitrary units; P <0.003; P = 0.001 for difference between treatments). Carvedilol also decreased oxidative stress significantly in mononuclear cells by 23 arbitrary units (95% CI: 15 to 31 arbitrary units; P <0.001), whereas propranolol decreased oxidative stress by 2 arbitrary units (95% CI: 7 to 12 arbitrary units; P = 0.62; P = 0.002 for difference between treatments). Carvedilol decreased C-reactive protein levels significantly by a median of 0.073 mg/dL (interquartile range, 0.034 to 0.112 mg/dL; P <0.001), whereas propranolol decreased levels by 0.012 mg/dL (interquartile range, 0.009 to 0.032 mg/dL; P = 0.26; P = 0.003 for difference between treatments). CONCLUSION: These findings suggest that carvedilol inhibits oxidative stress in polymorphonuclear and mononuclear cells, as well as lowers C-reactive protein levels, to a greater extent than does propranolol in hypertensive patients.

Adrenergic beta-Antagonists↗
PubMed2004

Role of microvascular permeability on physiologic differences in asthma and eosinophilic bronchitis.

Asthma and eosinophilic bronchitis are characterized by a similar type of eosinophilic inflammation. However, eosinophilic bronchitis differs from asthma in that there is no variable airflow obstruction or airway hyperresponsiveness. We evaluated the roles of vascular endothelial growth factor (VEGF) and microvascular permeability in causing these differences between the two diseases. Inflammatory indexes in induced sputum, exhaled nitric oxide levels, and vascular permeability index were examined in 11 normal control subjects, 19 beclomethasone dipropionate (BDP)-treated subjects with asthma, 20 non-BDP-treated subjects with asthma, and 17 patients with eosinophilic bronchitis. The percentage of eosinophils in sputum and exhaled nitric oxide levels were significantly higher in non-BDP-treated subjects with asthma and patients with eosinophilic bronchitis than in other two groups; however, VEGF levels and vascular permeability index were significantly higher in non-BDP-treated (VEGF: mean; 4,710 [SD; 1,150] pg/ml, p < 0.0001; vascular permeability index: 0.028 [0.009], p < 0.0001) and BDP-treated (2,560 [1,070] pg/ml, p = 0.0002; 0.016 [0.006], p = 0.004) subjects with asthma than in patients with eosinophilic bronchitis (1,120 [800] pg/ml; 0.01 [0.005]) and normal control subjects (1,390 [1,280] pg/ml; 0.008 [0.003]). We found significant correlations between the VEGF level and the airway vascular permeability index in all patient groups. Thus, interaction between airway microcirculation and VEGF may be a key element in differences in airway function between asthma and eosinophilic bronchitis.

Adult↗
PubMed2004

Enhanced coronary flow velocity during intra-aortic balloon pumping assessed by transthoracic Doppler echocardiography.

OBJECTIVES: The study was done to determine potential utility of measuring coronary flow velocity (CFV) by transthoracic Doppler echocardiography (TTDE) during intra-aortic balloon pumping (IABP). BACKGROUND: Use of IABP has been shown to increase CFV assessed by an invasive technique. The CFV in the left anterior descending coronary artery (LAD) can be measured by TTDE. METHODS: Coronary flow velocity in the distal LAD by TTDE was measured in 40 critically ill patients requiring IABP. All patients received emergency coronary angiography. Both CFV and pressure data were obtained during 1:2 balloon pumping. RESULTS: Adequate diastolic CFV recording was obtained in all patients. The IABP decreased systolic pressure and increased diastolic pressure. Average peak diastolic flow velocity and diastolic velocity time integral was 19 +/- 11 cm/s and 7.7 +/- 4.4 cm with non-augmented beat. These values were increased significantly (61 +/- 38%, 59 +/- 35%, p < 0.001) with augmented beat. Significant correlation was noted between % diastolic pressure augmentation and % increase in diastolic CFV (r = 0.62 to 0.69, p < 0.001). There was no significant difference in flow enhancement during IABP, irrespective to the proximal LAD stenosis severity (severe stenosis: 73 +/- 70%; intermediate stenosis: 61 +/- 29%; no significant stenosis: 58 +/- 29%; p = NS, analysis of variance). By continuous recording of CFV, the optimal timing of balloon control could be adjusted to maximize flow velocity during augmentation. CONCLUSIONS: Use of TTDE can be employed in monitoring CFV augmentation during IABP. The IABP produced significant distal flow enhancement even in patients with critical proximal stenosis. This totally noninvasive approach may help to optimize the benefits of IABP for coronary flow augmentation.

Adult↗
PubMed2004

Circulating monocytes and in-stent neointima after coronary stent implantation.

OBJECTIVES: The aim of this study was to investigate the relationship between circulating monocytes and in-stent neointimal volume at six-month follow-up. BACKGROUND: In-stent neointimal hyperplasia is the main contributing factor to in-stent restenosis. There is increasing evidence that white blood cells (WBCs), especially monocytes, play a central role in restenosis after stent implantation. METHODS: We performed coronary stent implantation in 107 patients (107 lesions). Peripheral blood was obtained from all patients immediately before coronary angiography and every day for seven days after the intervention, and each WBC fraction count was analyzed. At scheduled six-month follow-up, all patients received angiographic and volumetric intravascular ultrasound analysis. RESULTS: The circulating monocyte count increased and reached its peak two days after stent implantation (from 350 +/- 167 to 515 +/- 149/mm3, p < 0.01). The maximum monocyte count after stent implantation showed a significant positive correlation with in-stent neointimal volume at six-month follow-up (r = 0.44, p < 0.0001). Other fractions showed neither significant serial changes nor a correlation with in-stent neointimal volume. Multiple regression analysis revealed that in-stent neointimal volume was independently correlated with stent volume immediately after implantation (r = 0.45, p < 0.0001) and maximum monocyte count (r = 0.35, p < 0.001). Angiographic restenosis, defined as percent diameter stenosis >50%, was observed in 22 patients (21%), and these patients showed a significantly larger maximum monocyte count than patients without restenosis (642 +/- 110 vs. 529 +/- 77/mm3, p < 0.01). CONCLUSIONS: Circulating monocytes increased after coronary stent implantation, and the peak monocyte count related to in-stent neointimal volume. Our results suggest that circulating monocytes play a role in the process of in-stent neointimal hyperplasia.

Angioplasty, Balloon, Coronary↗
PubMed2004

Circadian variation of plaque rupture in acute myocardial infarction.

Studies have reported a circadian variation in the onset of acute myocardial infarction (AMI). Pathologic studies have revealed that plaque rupture is 1 of the major causes of AMI, but none of these has looked specifically at the circadian variation of plaque rupture. The aim of this study was to use intravascular ultrasound (IVUS) to investigate the circadian variation of plaque rupture in AMI. This study included 174 consecutive patients with AMI who underwent preinterventional IVUS. All patients were assigned to either a rupture group or a nonrupture group according to the preinterventional IVUS. In the 81 patients (47%) in the rupture group, the frequency of the onset of AMI increased significantly in the period from 6 A.M. to 12 P.M. compared with all other time periods (p <0.05). The clinical features of AMI in the rupture group were characterized as occurring significantly more at rest (67% vs 31%, p <0.01) and after significantly less preinfarction angina (22% vs 57%, p <0.01) compared with the nonrupture group. A different circadian variation was identified in the nonrupture group, characterized as a significant nocturnal nadir (12 to 6 A.M. compared with all other periods, p <0.05). The circadian variation of AMI is the result of a morning increase in incidence of plaque rupture.

Aged↗