Kazuhiko Nakazato
Fukushima Medical University
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Featured researches published by Kazuhiko Nakazato.
Circulation | 1999
Joji Shindo; Toshiyuki Ishibashi; Keiko Yokoyama; Kazuhiko Nakazato; Takayuki Ohwada; Masashi Shiomi; Yukio Maruyama
BACKGROUND A cytokine network is involved in atherogenesis. This study was conducted to investigate the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the development and composition of atherosclerotic lesions in Watanabe heritable hyperlipidemic (WHHL) rabbits. METHODS AND RESULTS GM-CSF (10 microg. kg-1. d-1) was administered to 4-month-old WHHL rabbits (n=9) 5 days a week for 7.5 months, whereas an equal dose of human serum albumin was administered to controls (n=9). The cholesterol levels were not changed significantly by the treatment. Age-matched 4-month-old rabbits (n=7) had atheromatous plaques over 30.7+/-5.7% of the inner surface area of the aortic arch. After treatment, the percentages of surface atheromatous plaques to total aortic arch area were 45.0+/-12.6% in the GM-CSF group and 74.3+/-11.0% in controls (P<0.0001). Histological examination demonstrated that GM-CSF reduced the ratio of intima to media (P<0.01) and cross-sectional areas of atherosclerotic lesions (P<0.0001). Quantitative analysis indicated a marked decrease in the areas of smooth muscle cells (P=0.0001), collagen (P=0.0001), and extracellular lipid deposits (P<0.05) of atheromatous plaques in GM-CSF-treated rabbits compared with controls. The terminal deoxynucleotidyltransferase-mediated dUTP-digoxigenin nick end-labeling (TUNEL) method and immunohistochemistry were performed to examine the relationship between decreased atherosclerotic lesions and apoptosis. The percentage of TUNEL-positive cells increased in the GM-CSF group (GM-CSF, 24.1+/-4.4% versus control, 11.6+/-3.2%; P<0.0001). GM-CSF enhanced the apoptosis of smooth muscle cells in the shoulder region and the fibrous cap (P<0.0001), suggesting one of the mechanisms for the antiatherogenic effect. CONCLUSIONS GM-CSF altered the composition of atherosclerotic lesions and reduced the atherosclerosis in WHHL rabbits.
European Journal of Heart Failure | 2013
Akiomi Yoshihisa; Satoshi Suzuki; Takayoshi Yamaki; Koichi Sugimoto; Hiroyuki Kunii; Kazuhiko Nakazato; Hitoshi Suzuki; Shu-ichi Saitoh; Yasuchika Takeishi
Effective pharmacotherapy for heart failure with preserved left ventricular ejection fraction (HFpEF) is still unclear. Sleep‐disordered breathing (SDB) causes cardiovascular dysfunction, giving rise to factors involved in HFpEF. However, it remains unclear whether adaptive servo‐ventilation (ASV) improves cardiovascular function and long‐term prognosis of patients with HFpEF and SDB.
The Journal of Clinical Pharmacology | 2013
Satoshi Suzuki; Akiomi Yoshihisa; Takayoshi Yamaki; Koichi Sugimoto; Hiroyuki Kunii; Kazuhiko Nakazato; Yukihiko Abe; Tomiyoshi Saito; Takayuki Ohwada; Hitoshi Suzuki; Shu-ichi Saitoh; Isao Kubota; Yasuchika Takeishi
Acute decompensated heart failure (ADHF) is a common and highly morbid cardiovascular disorder. Diuresis is a major therapy for the reduction of congestive symptoms. However, most diuretics cause hyponatremia, which is a worsening factor of ADHF patients prognosis. The purpose of this study was to examine the efficacy and safety of tolvaptan, which is a selective vasopressin V2 receptor antagonist and produces water excretion without changes in sodium excretion, compared with carperitide.
Journal of Hypertension | 2001
Kenji Nagata; Toshiyuki Ishibashi; Takayuki Sakamoto; Kazuhiko Nakazato; Yoshitane Seino; Keiko Yokoyama; Hiroshi Ohkawara; Tamio Teramoto; Yukio Maruyama
Objectives To clarify the pathophysiological significance of the renin–angiotensin system (RAS) in monocytes, we examined the effect of its blockade on tissue factor and plasminogen activator inhibitor-1 (PAI-1) synthesis in human cultured monocytes. Methods Monocytes were isolated from healthy volunteers and cultured. Tissue factor and PAI-1 antigens in culture medium and cells were measured by enzyme-linked immunosorbent assay and Western blotting, and mRNA levels were assessed by reverse-transcriptase polymerase chain reaction. Results We show that the RAS is present in isolated human peripheral blood monocytes. Exogenous angiotensin II increased the levels of tissue factor antigen and mRNA in cultured monocytes, but not of PAI-1 synthesis. An angiotensin converting enzyme (ACE) inhibitor (captopril) and an angiotensin II type 1 (AT1) receptor antagonist (candesartan) decreased the levels of tissue factor protein and mRNA in cultured monocytes. These alterations were accompanied by a reduction in the levels of tumour necrosis factor-α protein and mRNA. The levels of PAI-1 protein were reduced by captopril, but not by candesartan. A bradykinin B2 receptor antagonist abolished the suppressive effect of captopril on PAI-1 antigen. Conclusions An ACE inhibitor and an AT1 receptor antagonist reduced tissue factor synthesis in these cells. We show different actions of these agents on PAI-1 synthesis. ACE inhibition decreased PAI-1 synthesis mediated by bradykinin production, but AT1 receptor inhibition had no effect.
Coronary Artery Disease | 2001
Joji Shindo; Toshiyuki Ishibashi; Mikihiro Kijima; Kazuhiko Nakazato; Kenji Nagata; Keiko Yokoyama; Akira Hirosaka; Eiichi Sato; Hiroyuki Kunii; Nozomi Yamaguchi; Naohiko Watanabe; Takeo Saito; Kazuhira Maehara; Yukio Maruyama
BACKGROUND Although increased tissue factor expression is known in vulnerable plaques, there is no reported study to compare plaque fibrinolysis in stable and unstable plaques. This study investigates the extent of plasminogen activator inhibitor-1 (PAI-1) and apolipoprotein (a) [apo(a)] in the plaques of different types of coronary artery disease as well as the correlation between these molecules and infiltration of macrophages to plaques. METHODS Using immunohistochemical staining, we examined PAI-1 expression and apo(a) deposition in coronary atherosclerotic specimens obtained by directional coronary atherectomy from 19 patients with acute myocardial infarction (AMI), 12 with unstable angina pectoris (UAP), and 13 with stable angina pectoris (SAP). The percentages of the total areas of specimens stained with PAI-1 or apo(a) were estimated by an NIH image program. The proportion of macrophages as a percentage of all cells in plaques was calculated as the macrophage density. RESULTS We found significantly higher percentages of total areas of specimens stained with PAI-1 in AMI (25.5 +/- 8.6%, P < 0.001) and UAP (22.2 +/- 10.4%, P < 0.005) than in SAP (9.5 +/- 5.0%), as well as with apo(a) (AMI; 11.7 +/- 7.1%, P < 0.005, UAP; 11.1 +/- 5.5%, P < 0.01 versus SAP; 3.9 +/- 1.5%). Linear regression analysis of all the samples showed a correlation between PAI-1 or apo(a) and macrophage density (PAI-1: r = 0.75, P < 0.001 and apo(a): r = 0.56, P < 0.001). CONCLUSIONS Our results suggest a possible contribution of increased PAI-1 and apo(a) in plaques to the pathogenesis of acute coronary syndromes including impaired fibrinolysis.
Journal of Cardiology | 2012
Makiko Miyata; Akiomi Yoshihisa; Satoshi Suzuki; Shinya Yamada; Masashi Kamioka; Yoshiyuki Kamiyama; Takayoshi Yamaki; Koichi Sugimoto; Hiroyuki Kunii; Kazuhiko Nakazato; Hitoshi Suzuki; Shu-ichi Saitoh; Yasuchika Takeishi
BACKGROUND Cheyne-Stokes respiration (CSR-CSA) is often observed in patients with chronic heart failure (CHF). Although cardiac resynchronization therapy (CRT) is effective for CHF patients with left ventricular dyssynchrony, it is still unclear whether adaptive servo ventilation (ASV) improves cardiac function and prognosis of CHF patients with CSR-CSA after CRT. METHODS AND RESULTS Twenty two patients with CHF and CSR-CSA after CRT defibrillator (CRTD) implantation were enrolled in the present study and randomly assigned into two groups: 11 patients treated with ASV (ASV group) and 11 patients treated without ASV (non-ASV group). Measurement of plasma B-type natriuretic peptide (BNP) levels (before 3, and 6 months later) and echocardiography (before and 6 months) were performed in each group. Patients were followed up to register cardiac events (cardiac death and re-hospitalization) after discharge. In the ASV group, indices for apnea-hypopnea, central apnea, and oxyhemoglobin saturation were improved on ASV. BNP levels, cardiac systolic and diastolic function were improved with ASV treatment for 6 months. Importantly, the event-free rate was significantly higher in the ASV group than in the non-ASV group. CONCLUSIONS ASV improves CSR-CSA, cardiac function, and prognosis in CHF patients with CRTD. Patients with CSR-CSA and post CRTD implantation would get benefits by treatment with ASV.
Atherosclerosis | 2001
Kazuhiko Nakazato; Toshiyuki Ishibashi; Kenji Nagata; Yositane Seino; Yoko Wada; Takayuki Sakamoto; Reiko Matsuoka; Tamio Teramoto; Masayuki Sekimata; Yoshimi Homma; Yukio Maruyama
Although very low density lipoprotein (VLDL) receptor expression by macrophages has been shown in the vascular wall, it is not clear whether or not circulating monocytes express the VLDL receptor. We investigated the expression of VLDL receptor mRNA in human peripheral blood monocytes and monocyte-derived macrophages by reverse transcriptase polymerase chain reaction (RT-PCR) and nucleotide sequencing after subcloning of PCR product. VLDL receptor mRNA was detected both in peripheral blood monocytes and monocyte-derived macrophages. Expression of VLDL receptor mRNA was upregulated by hypoxia in monocytes, whereas treatment with oxidized LDL, interleukin-1beta or monocyte chemoattractant protein-1 did not affect the levels of VLDL receptor mRNA in monocytes and macrophages. The present study shows a novel response of VLDL receptor mRNA to hypoxia, suggesting a role for VLDL receptor in the metabolism of lipoproteins in the vascular wall and the development of atherosclerosis.
PLOS ONE | 2014
Satoshi Abe; Akiomi Yoshihisa; Mai Takiguchi; Takeshi Shimizu; Yuichi Nakamura; Hiroyuki Yamauchi; Shoji Iwaya; Takashi Owada; Makiko Miyata; Takamasa Sato; Satoshi Suzuki; Masayoshi Oikawa; Atsushi Kobayashi; Takayoshi Yamaki; Koichi Sugimoto; Hiroyuki Kunii; Kazuhiko Nakazato; Hitoshi Suzuki; Shu-ichi Saitoh; Yasuchika Takeishi
Aims Liver dysfunction due to heart failure (HF) is often referred to as cardiac or congestive hepatopathy. The composite Model for End-Stage Liver Disease excluding INR (MELD-XI) is a robust scoring system of liver function, and a high score is associated with poor prognosis in advanced HF patients with a heart transplantation and/or ventricular assist device. However, the impact of MELD-XI on the prognosis of HF patients in general remains unclear. Methods and Results We retrospectively analyzed 562 patients who were admitted to our hospital for the treatment of decompensated HF. A MELD-XI score was graded, and patients were divided into two groups based on the median value of MELD-XI score: Group L (MELD-XI <10, n = 289) and Group H (MELD-XI ≥10, n = 273). We compared all-cause mortality and echocardiographic findings between the two groups. In the follow-up period (mean 471 days), 104 deaths (62 cardiac deaths and 42 non-cardiac deaths) were observed. The event (cardiac death, non-cardiac death, all-cause death)-free rate was significantly higher in group L than in group H (logrank P<0.05, respectively). In the Cox proportional hazard analysis, a high MELD-XI score was found to be an independent predictor of cardiac deaths and all-cause mortality in HF patients. Regarding echocardiographic parameters, right atrial and ventricular areas, inferior vena cava diameter, and systolic pulmonary artery pressure were higher in group H than in group L (P<0.05, respectively). Conclusions The MELD-XI scoring system, a marker of liver function, can identify high-risk patients with right heart volume overload, higher pulmonary arterial pressure and multiple organ failure associated with HF.
American Journal of Cardiology | 2013
Hiroyuki Yamauchi; Akiomi Yoshihisa; Shoji Iwaya; Takashi Owada; Takamasa Sato; Satoshi Suzuki; Takayoshi Yamaki; Koichi Sugimoto; Hiroyuki Kunii; Kazuhiko Nakazato; Hitoshi Suzuki; Shu-ichi Saitoh; Yasuchika Takeishi
The occurrence of heart failure (HF) and its clinical features after a great disaster have not been rigorously examined. We retrospectively examined the effect of the Great East Japan Earthquake on the occurrence of decompensated HF. The number of patients admitted for treatment of decompensated HF and their clinical features were compared between 2 periods, March 11, 2011 to September 10, 2011 (after the earthquake) and the same period in the previous year. The number of admissions increased from 55 in 2010 to 84 in 2011. A comparison of the clinical features showed that the patients admitted after the earthquake had (1) older age (p = 0.031), (2) greater systolic blood pressure (p = 0.039), (3) a greater incidence of new-onset HF due to valvular heart disease (p = 0.040), (4) interruption of drugs (p = 0.001), (5) a greater incidence of infection (p = 0.019), (6) greater B-type natriuretic peptide (p = 0.005) and C-reactive protein (p = 0.003) levels, (7) a lower estimated glomerular filtration rate (p = 0.048) and lower albumin levels (p = 0.021), and (8) a larger diameter of the inferior vena cava (p = 0.008). In conclusion, these results suggest that the earthquake increased the incidence of HF in association with high blood pressure, interruption of drugs, inflammation, malnutrition, and fluid retention. Taking appropriate measures to control blood pressure, nutritional status, and hygiene environment might decrease the occurrence of HF in future disasters.
Journal of Cardiology | 2014
Akiomi Yoshihisa; Mai Takiguchi; Takeshi Shimizu; Yuichi Nakamura; Hiroyuki Yamauchi; Shoji Iwaya; Takashi Owada; Makiko Miyata; Satoshi Abe; Takamasa Sato; Satoshi Suzuki; Masayoshi Oikawa; Atsushi Kobayashi; Takayoshi Yamaki; Koichi Sugimoto; Hiroyuki Kunii; Kazuhiko Nakazato; Hitoshi Suzuki; Shu-ichi Saitoh; Yasuchika Takeishi
BACKGROUND Chronic obstructive pulmonary disease (COPD) often coexists with heart failure (HF), and is considered to be associated with adverse outcomes in HF patients. However, the features of cardiovascular function and the detailed all-cause mortality of HF with COPD remain unclear. METHODS AND RESULTS Consecutive 378 patients admitted for HF who underwent spirometry were divided into three groups: HF without COPD (non-COPD group, n=272), HF with mild COPD (GOLD I group, n=82), and HF with moderate COPD (GOLD II group, n=24). The GOLD II group, as compared to non-COPD group, had (1) higher troponin T (p=0.009); (2) greater cardio-ankle vascular index (p=0.032); and (3) similar cardiac systolic and diastolic function of the right and left ventricle. In addition, rates of cardiac (p=0.049), non-cardiac (p=0.001), and all-cause mortality (p=0.002) were higher in GOLD II group than in non-COPD and GOLD I groups. Importantly, in the Cox proportional hazard analyses, the GOLD stage II was an independent predictor of cardiac (p=0.038), non-cardiac (p=0.036), and all-cause mortality (p=0.015) in HF patients. CONCLUSIONS HF patients with coexistent moderate COPD (GOLD stage II) have greater myocardial damage, greater arterial stiffness, and higher cardiac and non-cardiac mortality.