Tomoaki Nagao

Ehime University, Matuyama, Ehime, Japan

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Publications (24)21.32 Total impact

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    ABSTRACT: Hyperhomocystemia has been reported to be associated with cardiovascular disease, especially stroke. The resistive index (RI) estimated by carotid ultrasound is an established variable for estimating the risk of cerebral infarction. The aim of this study was to evaluate the relationship between homocysteine concentration and carotid RI, a marker of cerebral vascular resistance in essential hypertensive patients. We measured serum total homocysteine and carotid RI in 261 patients. Multiple linear regression analysis was used to determine the association of homocysteine with carotid RI and intima media thickness (IMT). Age, sex, BMI, systolic blood pressure (SBP), homocysteine, total cholesterol, high density lipoprotein-cholesterol (HDL-C), uric acid, CRP, HbA1c, estimated glomerular filtration rate, and use of antihypertensive agents were included as independent variables. Age, sex, use of antihypertensive agents, HDL-C and homocysteine levels were shown to be significant predictors of carotid RI, but not IMT. Multiple regression analysis in men older than 65 years showed homocysteine and SBP were associated significantly with carotid RI. In elderly male patients, homocysteine was the strongest predictor of carotid RI (B = 0.0068, CI = 0.0017-0.0120, P = 0.011) in the multivariate model. In conclusion, hyperhomocysteinemia is associated with carotid RI, a surrogate marker of cerebral vascular resistance, especially in elderly men.
    Scientific reports. 01/2014; 4:5663.
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    ABSTRACT: Kimura's disease is a granulomatous disease of unknown origin that develops in the dermis, subcutaneous tissue and lymph nodes. Kimura's disease is frequently complicated by nephropathy, particularly membranous nephropathy (MN). It has recently been suggested that glomerular immunoglobulin (IgG)4 deposition may play a role in the pathogenesis of idiopathic MN. These IgG4 antibodies are thought to react with antigens, primarily the phospholipase A2 receptor (PLA2R) expressed on the podocyte cell membrane. We herein report a case of Kimura's disease with MN in which a renal biopsy specimen revealed positive staining for anti-IgG4 and anti-PLA2R antibodies.
    Internal medicine (Tokyo, Japan). 01/2014; 53(13):1435-40.
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    ABSTRACT: In the treatment of hypertension, once-daily administration of long-acting antihypertensive drugs has been recommended for the improvement of treatment adherence; however, it is unclear whether dividing daily doses has the additional benefit of more ideal blood pressure (BP) control over a 24-hour period. The aim of the study was to investigate whether dividing a 10-mg daily dose of amlodipine, a long-acting calcium channel blocker, is associated with increased trough plasma amlodipine concentrations, reduced arterial stiffness, and improved BP control over a 24-hour period. Outpatients with essential hypertension were included this open-label, 2-period crossover study. The patients were administered amlodipine 10 mg/d in 2 divided doses for 8 weeks. At week 4, blood was collected just before amlodipine administration for the evaluation of trough plasma amlodipine concentrations. At week 8, 24-hour, daytime, nighttime, and early morning BP, as well as arterial stiffness, were measured using ambulatory BP monitoring (ABPM) and cardio-ankle vascular index (CAVI), respectively. In the subsequent study period, amlodipine 10 mg/d was administered once daily, and the same tests were performed at the same timings as in period 1. Ten patients were enrolled (7 men, 3 women; mean age, 61.0 [15.3] years). Mean 24-hour BP with twice-daily administration was not significantly lower than that with once-daily administration (129.7 [7.3]/80.1 [7.9] mm Hg vs 130.5 [11.8]/80.1 [7.9] mm Hg, respectively). Similarly, there were no significant differences in daytime, nighttime, or early morning BP between twice- and once-daily administration. In addition, the differences in trough plasma amlodipine concentrations (22.37 [7.66] ng/mL vs 20.57 [8.22] ng/mL) and CAVI values (8.2 [1.8] vs 8.5 [1.0]) were not significantly different between twice- and once-daily administration. Administering amlodipine in 2 divided doses was not associated with increased trough plasma amlodipine concentrations, reduced arterial stiffness, or improved BP control over a 24-hour period in patients with essential hypertension. UMIN Clinical Trials Registry no. UMIN000003914.
    Clinical Therapeutics 08/2013; · 2.23 Impact Factor
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    ABSTRACT: Left ventricular hypertrophy (LVH) regression is an important issue in hypertensive patients. Patients with LVH who had received the angiotensin receptor blocker (ARB) treatment for 8 weeks and had not reached the target blood pressure level were enrolled in the study. Patients were assigned to either losartan (50 mg)/hydrochlorothiazide (HCTZ, 12.5 mg) group or ARB + CCB group (usual dose of ARB and calcium channel blocker, CCB). After 48 weeks, LV mass index was found to be reduced significantly in the losartan/HCTZ group but not in the ARB + CCB group. These results suggest that combination therapy of an ARB and diuretic has greater potential to cause regression compared with an ARB and CCB.
    Clinical and Experimental Hypertension 02/2013; · 1.28 Impact Factor
  • Nihon Naika Gakkai Zasshi 01/2013; 102(1):140-2.
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    ABSTRACT: Urinary type IV collagen excretion (uT4C) in diabetic patients is higher than in normal subjects. In this study, we investigated the relationship between uT4C and renal hemodynamics in 42 patients with essential hypertension. The renal resistive index (RI) is calculated from blood flow velocities measured using pulsed-wave in interlobar arteries. There was a significant correlation between uT4C to creatinine ratio (uT4C/uCr) and age, hemoglobin A1c (HbA1c), and RI. A stepwise regression analysis showed that RI was independently associated with uT4C/uCr. These results indicated that uT4C may be a marker of renovascular stiffness due to glomerulosclerosis in patients with essential hypertension.
    Clinical and Experimental Hypertension 05/2012; · 1.28 Impact Factor
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    ABSTRACT: Osteopontin (OPN) has been implicated in the pathology of several renal conditions. The aim of this study was to clarify the roles of OPN in diabetic nephropathy. Diabetes mellitus (DM) was induced in wild-type (WT) and OPN knockout (KO) mice by injecting streptozotocin. The mice were killed 20 weeks after induction of DM and their kidneys removed. Renal mRNA expression of OPN was increased in WT-DM mice compared to WT-sham mice. Immunohistochemistry showed high levels of OPN expression in the proximal tubules of WT-DM mice. Kidney weight and urinary albumin excretion increased to similar levels in the WT-DM and KO-DM mice. Interstitial fibrosis was increased in WT-DM mice compared to KO-DM mice. However, there were no differences in the degree of mesangial expansion or glomerular hypertrophy between the two groups. F4/80-positive cells (macrophages) and FSP-1-positive cells (fibroblasts) showed significantly higher infiltration in WT-DM mice than in KO-DM mice. Renal mRNA expression of NADPH oxidase subunits and urinary 8-isoprostane excretion were also increased in WT-DM mice. These results indicated that OPN is a key molecule that induces interstitial fibrosis in the diabetic kidney, but does not induce glomerular sclerosis.
    Nephron extra. 01/2012; 2(1):87-103.
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    ABSTRACT: An 80-year-old woman was referred to the Division of Nephrology at Ehime University Hospital because of leg edema in December 2010. She had been treated with 300 mg of tocopherol for scleroderma since 2007 and treated with 9 mg of prednisolone (PSL) for autoimmune hearing loss since 2010. Due to the occurrence of mild hematuria (5-9/HPF), proteinuria (0.9 g/day) and an increased serum creatinine level (1.31 mg/dL), a renal biopsy was performed. Light microscopy (LM) showed minor abnormality in the glomeruli, and immunohistology showed the absence of deposits of immunoglobulins and complements. Electron microscopy (EM) showed a thin glomerular basement membrane with a limited level of podocyte abnormalities. Due to the findings of intimal thickening of interlobular arteries and subcapsular accumulation of global sclerosis on LM, she was diagnosed with nephrosclerosis and thin basement membrane disease. Four weeks later, her leg edema had increased considerably and urinary protein had increased to 12.4 g/day. The second biopsy showed similar findings in LM and IF as the first biopsy, but EM revealed diffuse foot process effacement. She was diagnosed with minimal change nephrotic syndrome (MCNS) and treated with methylprednisolone pulse therapy followed by 40 mg of oral PSL. Her urinary protein had completely disappeared 6 weeks later. Complete remission with PSL treatment indicates that urinary protein at first renal biopsy was due to MCNS. Our case exhibited podocyte features in the incipient phase of human MCNS.
    Nippon Jinzo Gakkai shi 01/2012; 54(8):1192-6.
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    ABSTRACT: Osteopontin (OPN) has been implicated in the pathology of several renal conditions. Recently, we demonstrated in vitro that aldosterone has important roles in collagen synthesis by inducing OPN (Irita J, Okura T, Kurata M, Miyoshi K, Fukuoka T, Higaki J. Hypertension 51: 507-513, 2008). The aim of the present study was to clarify the roles of OPN in aldosterone-mediated renal fibrosis by infusing aldosterone into either wild-type (WT) or OPN knockout mice (OPN(-/-)). We used uninephrectomized mice treated with aldosterone and high salt to exacerbate renal fibrosis. After 4 wk of treatment with aldosterone, we showed similar increases in systolic blood pressure in both strains of mice. Urine albumin excretion was greater in aldosterone-infused WT mice than in aldosterone-infused OPN(-/-) mice. Immunohistochemical analysis showed high levels of OPN expression in aldosterone-infused WT mice. Interstitial fibrosis and inflammatory infiltrations were increased in aldosterone-infused WT mice compared with either vehicle-infused WT or aldosterone-infused OPN(-/-) mice. These changes were ameliorated markedly by eplerenone treatment in aldosterone-infused WT mice. Aldosterone-infused WT mice also had increased expression of NADPH oxidase subunits compared with aldosterone-infused OPN(-/-) mice. We observed a marked increase in oxidative stress markers in aldosterone-infused WT mice compared with aldosterone-infused OPN(-/-) mice. These results indicate that OPN is a promoter of aldosterone-induced inflammation, oxidative stress, and interstitial fibrosis in the kidney and suggest that inhibition of OPN may be a potential therapeutic target for prevention of renal injury.
    AJP Renal Physiology 07/2011; 301(4):F833-44. · 4.42 Impact Factor
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    ABSTRACT: Osteopontin (OPN) has recently emerged as a key factor in both vascular remodelling and development of atherosclerosis. It has been reported that OPN is regulated by the renin-angiotensin-aldosterone system (RAAS). The aim of this study was to clarify the effect of angiotensin II receptor blockade with valsartan on plasma OPN levels in patients with essential hypertension (EHT). Forty-six patients (mean age, 64±11 years) with EHT were randomly assigned to treatment with amlodipine or valsartan. There were no significant differences in baseline clinical characteristics between the two groups. Blood sampling and blood pressure evaluation were performed before and after 24 weeks of treatment. After 24 weeks, both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were decreased significantly and by the same degree in each treatment group. However, valsartan but not amlodipine decreased plasma OPN levels (baseline and 24-week data-valsartan: 614±224 ng ml(-1), 472±268 ng ml(-1), P=0.006; amlodipine: 680±151 ng ml(-1), 687±234 ng ml(-1), P>0.999). A positive correlation between the reduction in OPN and the log natural (ln) C-reactive protein (CRP) was seen in the valsartan-treated group. Stepwise regression analysis showed that treatment with valsartan and the reduction of ln CRP were associated with the reduction in OPN levels, and this association was independent of the reduction in SBP or aldosterone levels (valsartan: β=0.332, P=0.026; ln CRP reduction: β=0.366, P=0.015). These results suggest that suppression of the RAAS and inflammation may decrease plasma OPN levels.
    Journal of human hypertension 05/2011; 25(5):334-9. · 2.80 Impact Factor
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    ABSTRACT: A 70-year-old woman was admitted to our hospital because of sudden hearing loss. She was treated with intratympanic dexamethasone, but her hearing impairment progressed. After admission, she developed scleritis of her left eye. Laboratory findings included elevated white blood cell count and C-reactive protein level, microhematuria, and proteinuria. Serology was positive for myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA), but negative for proteinase 3 (PR3)-ANCA. Renal biopsy revealed a single glomerulus with extensive glomerular tuft necrosis, indicating necrotizing vasculitis. She was diagnosed with MPO-ANCA-associated polyangiitis. ANCA-related polyangiitis should be considered in the differential diagnosis of sudden deafness or scleritis.
    Internal Medicine 01/2011; 50(16):1725-8. · 0.97 Impact Factor
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    ABSTRACT: Serum cystatin C is not only a marker of renal function but also acts as an independent risk factor for cardiovascular damage, heart failure, and death. It is known that the initiation and progression of these cardiovascular events contributes to renal dysfunction and chronic inflammation. In this study, we investigated the relationship between cystatin C and proinflammatory cytokines. Eighty-eight patients with essential hypertension participated in the study, which involved measuring proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C reactive protein (CRP). Positive correlations were detected between cystatin C and estimated glomerular filtration rate (eGFR) (r = -0.503, p < 0.001), systolic blood pressure (r = -0.246, p = 0.034), and pulse pressure (r = -0.295, p = 0.010). In contrast, serum creatinine correlated only with eGFR (r = -0.755, p < 0.001) and eGFR correlated only with age (r = -0.339, p = 0.001) and not with the other clinical parameters, whereas cystatin C also correlated with log natural (ln) IL-6 (r = -0.247, p = 0.033) and ln TNF-α (r = -0.405, p < 0.001) but not with CRP (r = -0.188, p = 0.108). In contrast, plasma creatinine and eGFR did not correlate with any of these proinflammatory cytokines. Stepwise regression analysis showed that ln TNF-α, eGFR and pulse pressure were independent determinants of serum cystatin C concentration. This study showed that cystatin C is a marker of inflammation as well as renal function.
    Clinical and Experimental Nephrology 12/2010; 14(6):584-8. · 1.25 Impact Factor
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    ABSTRACT: The development of vascular calcification is an active, highly regulated process with similarities to bone formation. Osteocalcin (OC), a vitamin K-dependent protein expressed by osteoblasts, contains 3 gamma-carboxyglutamic acid residues derived from the vitamin K-dependent posttranslational modification of glutamic acid residues. Circulating undercarboxylated OC (ucOC) is increased in vitamin K deficiency and serum ucOC is reported to be a clinical marker of vitamin K status. Vitamin K deficiency is associated with vascular calcification as well as osteoporosis. We evaluated the relationship between ucOC and carotid artery calcification in 92 patients with essential hypertension. Ultrasound of the common carotid artery was performed to identify vascular calcification and subjects were divided into 2 groups: a calcification (+) group and a calcification (-) group. Serum creatinine and ucOC levels were higher in the calcification (+) group than in the calcification (-) group and serum ucOC correlated with serum creatinine. To identify the independent determinant factor for carotid artery calcification, we applied both ucOC and estimated glomerular filtration rate as independent factors in logistic regression analysis. Serum ucOC was an independent determinant of carotid calcification, suggesting that circulating ucOC may be an important biomarker of carotid artery calcification.
    Kidney and Blood Pressure Research 03/2010; 33(1):66-71. · 1.60 Impact Factor
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    ABSTRACT: The renin angiotensin aldosterone system (RAAS) induces inflammation and accelerates atherosclerosis, contributes to both pro- and anti-inflammatory cytokines. Osteopontin (OPN) is known as a pro-inflammatory cytokine and adiponectin is known as an anti-inflammatory cytokine. C-reactive protein (CRP) not only reflects an inflammatory state but also leads to inflammation. Previous studies clarified that OPN and adiponectin were regulated by RAAS. In this study, we hypothesized that plasma OPN level relates to serum adiponectin level in patients with essential hypertension (EHT). Sixty-two patients (32 females) with EHT were enrolled in this study. They were evaluated for conventional risk factors for atherosclerosis, further plasma aldosterone, plasma OPN, serum adiponectin, and CRP levels were assayed. There were significant gender differences in creatinine, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-denisty lipoprotein(LDL) cholesterol, log transformed (ln) adiponectin and ln CRP. Osteopontin was correlated positively with aldosterone and ln CRP (r = 0.277, p = 0.029, r = 0.278, p = 0.029, respectively), negatively with adiponectin (r = -0.346, p = 0.006). Ln adiponectin was correlated positively with HDL cholesterol (r = 0.373, p = 0.003) and negatively with gender (male as 1), creatinine, triglyceride, aldosterone, and ln CRP (r = -0.55, p < 0.001, r = -0.279, p = 0.028, r = -0.406, p = 0.001, r = -0.307, p < 0.015, r = -0.289, p = 0.023, respectively). Stepwise regression analysis showed that adiponectin was an independent predictor of OPN β= -0.0339, p = 0.004). Our results suggest that OPN and adiponectin are related to each other underlying the mechanisms of RAAS and inflammation.
    Clinical and Experimental Hypertension 01/2010; 32(6):358-63. · 1.28 Impact Factor
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    ABSTRACT: An 81-year-old man was admitted to our hospital because of leg edema. Serological studies for anti-neutrophil cytoplasmic antibody (ANCA), anti-double stranded DNA antibodies, and antibodies to hepatitis C and B were negative. Severe hypocomplementemia was present and a cryoglobulin was detected with serum immunoelectrophoresis being positive for the immunoglobulin (Ig)M kappa type. The cryoglobulin was characterized by immunoelectrophoresis which showed that the protein was composed of polyclonal IgG and kappa-type monoclonal IgM. A diagnosis of essential type II cryoglobulinemia was made and the patient underwent a renal biopsy. The renal biopsy revealed endocapillary and mesangial cell proliferation with increased matrix. The resultant lobular appearance of the glomerulus and double contours of the basement membrane were indicative of membranoproliferative glomerulonephritis (MPGN). Immunofluorescence studies demonstrated granular staining in the capillary wall for IgG, IgA, IgM and C4 with little C3 deposition but no C1q. He was finally diagnosed with MPGN due to mixed cryoglobulinemia type II. MPGN with essential cryoglobulinemia type II without evidence of hepatitis C virus infection, like that found in the present case, is very rare.
    Geriatrics & Gerontology International 04/2009; 9(1):92-6.
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    ABSTRACT: A 64-year-old woman was admitted because of leg edema. Fifteen years previously she had been diagnosed with monoclonal gammopathy of undetermined significance (MGUS). Urinary immunoelectrophoresis demonstrated positivity for IgA kappa light chains. Bone marrow aspiration revealed a mild plasmacytosis. Her renal biopsy specimen revealed thickened basement membrane, mesangial cell proliferation and an increase in the mesangial matrix. Immunofluorescence studies showed the deposition of kappa light chains in the capillary wall and nodular lesions. These findings confirmed a diagnosis of light chain deposit disease (LCDD) with MGUS. The development of LCDD in patients with MGUS for fifteen years is very rare.
    Internal Medicine 02/2009; 48(2):101-4. · 0.97 Impact Factor
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    ABSTRACT: A 53-year-old man was admitted to Ehime University Hospital because of a left adrenal tumor, which was detected by a routine medical examination. Blood pressure was 124/74 mmHg and the pulse rate was 80/min and regular. Computed tomography showed the tumor consisting mainly of low-density areas and partly of heterogeneous density areas. Magnetic resonance imaging demonstrated that the tumor consisted mainly of low intensity areas, partly of heterogeneous intensity areas determined by T1-weighted images; T2-weighted images showed that the tumor consisted mainly of high intensity areas and partly of heterogeneous intensity areas. These images suggested that the left adrenal tumor was a pheochromocytoma. The concentrations of serum adrenaline and noradrenaline were slightly elevated (adrenaline 0.11 ng/mL (normal: < 0.1) and noradrenaline 1.11 ng/mL (normal 0.1 - 0.5)). Although 131I-meta-iodobenzylguanidine (MIBG) scintigraphy did not show an accumulation of the tracer, 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) showed an increased accumulation of the tracer in the left adrenal tumor. These results were suggestive of the diagnosis of pheochromocytoma, and left adrenalectomy was performed by endoscopy. He was finally diagnosed with pheochromocytoma. The detection rate of pheochromocytoma by FDG-PET is not very high and has been reported to be about 70 %. However, FDG-PET may be useful for detecting local recurrence or distant metastasis, in patients with MIBG-negative pheochromocytoma.
    Nippon Jinzo Gakkai shi 02/2009; 51(5):563-8.
  • CVD Prevention and Control 01/2009; 4.
  • International Journal of Cardiology - INT J CARDIOL. 01/2009; 137.
  • International Journal of Cardiology - INT J CARDIOL. 01/2009; 137.