Researchers Database

iwazu yoshitaka

    Doctoral Course of Medical Science Programs of Human Biology Division of  Associate Professor
Last Updated :2021/10/17

Researcher Information

J-Global ID

Research Interests

  • Calciprotein particle (CPP)   高血圧   NaCl   ミネラルコルチコイド   腎線維化   

Research Areas

  • Other / Other / Laboratory medicine
  • Life sciences / Nephrology


  •        - 2008  Jichi Medical University  医学研究科  地域医療学系腎臓内科学
  •        - 1999  Miyazaki Medical College  医学部  医学科

Association Memberships


Published Papers

  • Yoshitaka Iwazu, Takaomi Minami, Kazuhiko Kotani
    ANGIOLOGY 68 (3) 189 - 195 0003-3197 2017/03 [Refereed][Not invited]
    Kawasaki disease (KD) is an acute childhood febrile disease of unknown etiology. It exhibits not only coronary artery aneurysms in some cases but also systemic vasculitis. Whether KD is associated with accelerated atherosclerosis remains debatable. The measurement of pulse wave velocity (PWV) is useful as a simple, noninvasive measurement of arterial stiffness, an atherosclerotic manifestation. We herein present a systematic review of clinical studies that focused on PWV in patients with KD. A PubMed-based search identified 8 eligible studies published until June 2015. The PWV of patients with KD, regardless of antecedent coronary artery lesions, was high relative to controls, even though their blood pressure appeared to be similar. Although definitive conclusions cannot be made with the limited information, patients with KD may be at risk of systemic atherosclerosis in association with arterial stiffness. Further research, including longitudinal and outcome studies, is needed to determine the clinical significance of a potential increase in PWV in patients with KD.
  • Yoshitaka Iwazu, Satoko Komori, Daisuke Nagata
    THERAPEUTIC APHERESIS AND DIALYSIS 19 (1) 97 - 98 1744-9979 2015/02 [Refereed][Not invited]
  • Tomoyuki Yamazaki, Tetsu Akimoto, Kousuke Okuda, Taro Sugase, Eri Takeshima, Akihiko Numata, Yoshiyuki Morishita, Yoshitaka Iwazu, Hiromichi Yoshizawa, Takanori Komada, Kana Iwazu, Osamu Saito, Fumi Takemoto, Shigeaki Muto, Eiji Kusano
    INTERNAL MEDICINE 53 (2) 115 - 119 0918-2918 2014 [Refereed][Not invited]
    Mixed cryoglobulinemia is occasionally seen in patients with hepatitis B virus (HBV) infection. This report presents the case of a quiescent HBV carrier who had type II mixed cryoglobulinemia, protracted purpura, ulcerative skin lesions and advanced chronic kidney disease. The cutaneous manifestations of the patient improved along with a decrease in the serum cryoglobulin and HBV-deoxyribonucleic acid levels following the initiation of oral entecavir in combination with plasmapheresis. However, the patient ultimately required prednisolone due to the limited benefits of these treatments. We also discuss various concerns regarding steroid treatment in patients with mixed cryoglobulinemia complicated by HBV infection.
  • Yoshitaka Iwazu, Shigeaki Muto, Yukio Miyata, Masanori Ochi, Akihiko Tokue, Yasushi Asano, Eiji Kusano
    CLINICAL NEPHROLOGY 79 (1) 81 - 84 0301-0430 2013/01 [Refereed][Not invited]
    A 50-year-old female patient who presented with intermittent gross hematuria was referred to our hospital. Three-dimensional computed tomography (3D-CT) revealed a left renal arteriovenous malformation (AVM). Because she declined to undergo additional therapy including surgical treatment, we observed the clinical course of renal AVM for 7 years using 3D-CT. When the 3D-CT showed gradual enlargement of the aneurysms concurrent with the onset of clinical symptoms (cardiomegaly and hypertension), we performed simple left nephrectomy. After the operation, the cardiomegaly and hypertension returned to normal, and gross hematuria did not recur. Based on the macro-anatomical findings of the resected kidney and the observation of the natural course, this case strongly supported the hypothesis that the renal AVM had existed from birth and enlarged gradually to eventually produce the typical signs and symptoms.
  • Tetsu Akimoto, Kazuhiro Shiizaki, Taro Sugase, Yuko Watanabe, Hiromichi Yoshizawa, Naoko Otani, Akihiko Numata, Eri Takeshima, Tomoyuki Yamazaki, Takuya Miki, Chiharu Ito, Johanne V Pastor, Yoshitaka Iwazu, Osamu Saito, Shigeaki Muto, Makoto Kuro-o, Eiji Kusano
    Clinical and experimental nephrology 16 (3) 442 - 7 1342-1751 2012/06 [Refereed][Not invited]
    BACKGROUND: Klotho has been investigated as an anti-aging protein that is predominantly expressed in the distal convoluted tubules in the kidneys and in the choroid plexus of the brain. The purpose of the present study was to determine the relationship between the soluble form of Klotho and renal function in chronic peritoneal dialysis (PD) patients, a relationship which remains poorly understood. METHODS: The soluble Klotho levels in the serum, urine, and peritoneal dialysate obtained from thirty-six PD patients were determined by a sandwich enzyme-linked immunosorbent assay system. RESULTS: The amount of urinary excreted soluble Klotho over 24 h ranged from 1.54 to 1774.4 ng/day (median 303.2 ng/day; interquartile range [IR] 84.1-498.5), while the serum soluble Klotho concentration ranged from 194.4 to 990.4 pg/ml (mean 553.7 ± 210.4 pg/ml). The amount of urinary Klotho excretion was significantly correlated with residual renal function. However, there was no apparent correlation between the serum soluble Klotho levels and the residual renal function. Klotho was also detected in the 24-h dialysate collections. There was a significant correlation between the peritoneal Klotho excretion and the amount of albumin contained in the dialysate collections (r = 0.798, p < 0.01). CONCLUSIONS: The total amount of urinary excreted Klotho, but not the serum level of soluble Klotho, may be a potential biomarker for assessing the residual renal function among PD patients. Whether our findings are also valid for chronic kidney disease patients overall should therefore be evaluated in greater detail.
  • Yoshitaka Iwazu, Tetsu Akimoto, Sayoko Izawa, Makoto Inoue, Shigeaki Muto, Yasuhiro Ando, Kana Iwazu, Noriyoshi Fukushima, Wako Yumura, Eiji Kusano
    CLINICAL AND EXPERIMENTAL NEPHROLOGY 16 (3) 485 - 489 1342-1751 2012/06 [Refereed][Not invited]
    We describe a case of an adult female who presented with nephrotic syndrome. She was diagnosed with systemic lupus erythematosus with serum antinuclear antibodies, leucopenia with lymphopenia, butterfly erythema, and nephrotic syndrome. Renal biopsy revealed normal glomeruli with diffuse effacement of the foot processes, consistent with lupus podocytopathy. Although human albumin replacement was performed initially, acute renal failure developed rapidly. Therefore, she was treated with double filtration plasmapheresis (DFPP) in addition to oral steroid. After steroid therapy combined with DFPP, the renal function and proteinuria improved rapidly. Although the impact of DFPP on the treatment of lupus nephritis remains to be delineated, our observations suggest that DFPP in lupus podocytopathy played a pivotal role in facilitating the early recovery from renal injuries. Because of the rapid improvement of renal function without any change in body weight by DFPP, acute renal failure in the setting of lupus podocytopathy might contribute to an alternative pathophysiological factor for the diminished glomerular filtration rate, similar to that observed in the setting of idiopathic minimal change glomerulopathy.
  • Takahiro Masuda, Sumiko Honma, Nobuhiro Sasaki, Shiho Hanawa-Yazawa, Yoshitaka Iwazu, Eiji Kusano, Yasushi Asano
    CKJ: Clinical Kidney Journal 5 (3) 257 - 260 2048-8505 2012/06 [Refereed][Not invited]
    Obstructive sleep apnea (OSA) is common in patients with renal disease, and an association between OSA and proteinuria has been proposed. However, the effect on proteinuria of OSA treatment with continuous positive airway pressure (CPAP) is unknown. We experienced a case of severe OSA, where proteinuria was clearly improved after CPAP initiation without any changes of medication or body weight. The remarkable reduction of repetitive apnea and hypopnea by CPAP might ameliorate proteinuria by lessening renal hypoxia and sympathetic nerve activation. This case suggests that CPAP is a promising option for OSA with proteinuria. © 2012 The Author. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.
  • Shin-ichi Takeda, Junko Chinda, Takashi Murakami, Akihiko Numata, Yoshitaka Iwazu, Tetsu Akimoto, Yoshitomo Hamano, Shigeaki Muto, Masafumi Takahashi, Eiji Kusano
    NEPHROLOGY DIALYSIS TRANSPLANTATION 27 (5) 1786 - 1792 0931-0509 2012/05 [Refereed][Not invited]
    Background. It has been well-recognized that cancer patients occasionally develop renal disorders independently of direct tumor invasion. However, the clinical entity of paraneoplastic glomerulopathy remains poorly understood, in part due to the lack of an animal model for basic research. In the present study, we investigated whether cancer-bearing rats develop features of glomerulopathy. Methods. RCN-9 rat colon cancer cells (1 x 10(7)) were injected into F344 rats (n = 13) and T cell-deficient F344 rats (nude rats; n = 7) via the portal system. Urinalysis and histological examinations were performed in comparison with control rats (n = 6) that received a vehicle injection. Results. Metastatic growth of RCN-9 cells exclusively in the liver was observed in the cancer-injected F344 rats, whereas direct invasion into the kidney was not evident even microscopically. Two of the cancer-injected F344 rats died within 2 days, but 9 of the 11 that avoided early death showed elevation of urinary protein (up to 158.0 mg/day) compared to controls (mean values: 60.8 +/- 12.9 versus 17.8 +/- 2.1 mg/day, P = 0.0291). Although morphological changes were not evident in light microscopy, abundant IgG in the glomerular tufts of the proteinuric rats was shown immunohistochemically. Ultrastructure analysis revealed electron-dense deposits in the glomerular basement membrane zone and effacement of the podocytic foot process. Interestingly, none of the nude rats showed proteinuria despite of cancer growth, suggesting that a specific immune response was involved. Conclusions. The tumor-bearing rats developed features of glomerulopathy, as expected from the clinical perspective, and this animal model may provide new insights into the development of paraneoplastic glomerulopathies.
  • Takahiro Masuda, Shigeaki Muto, Genro Fujisawa, Yoshitaka Iwazu, Mariko Kimura, Takahisa Kobayashi, Mutsuko Nonaka-Sarukawa, Nobuhiro Sasaki, Yuko Watanabe, Masami Shinohara, Takashi Murakami, Kazuyuki Shimada, Eiji Kobayashi, Eiji Kusano
    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY 302 (9) H1871 - H1883 0363-6135 2012/05 [Refereed][Not invited]
    Masuda T, Muto S, Fujisawa G, Iwazu Y, Kimura M, Kobayashi T, Nonaka-Sarukawa M, Sasaki N, Watanabe Y, Shinohara M, Murakami T, Shimada K, Kobayashi E, Kusano E. Heart angiotensin II-induced cardiomyocyte hypertrophy suppresses coronary angiogenesis and progresses diabetic cardiomyopathy. Am J Physiol Heart Circ Physiol 302: H1871-H1883, 2012. First published March 2, 2012; doi:10.1152/ajpheart.00663.2011.-To examine whether and how heart ANG II influences the coordination between cardiomyocyte hypertrophy and coronary angiogenesis and contributes to the pathogenesis of diabetic cardiomyopathy, we used Spontaneously Diabetic Torii (SDT) rats treated without and with olmesartan medoxomil (an ANG II receptor blocker). In SDT rats, left ventricular (LV) ANG II, but not circulating ANG II, increased at 8 and 16 wk after diabetes onset. SDT rats developed LV hypertrophy and diastolic dysfunction at 8 wk, followed by LV systolic dysfunction at 16 wk, without hypertension. The SDT rat LV exhibited cardiomyocyte hypertrophy and increased hypoxia-inducible factor-1 alpha expression at 8 wk and to a greater degree at 16 wk and interstitial fibrosis at 16 wk only. In SDT rats, coronary angiogenesis increased with enhanced capillary proliferation and upregulation of the angiogenic factor VEGF at 8 wk but decreased VEGF with enhanced capillary apoptosis and suppressed capillary proliferation despite the upregulation of VEGF at 16 wk. In SDT rats, the phosphorylation of VEGF receptor-2 increased at 8 wk alone, whereas the expression of the antiangiogenic factor thrombospondin-1 increased at 16 wk alone. All these events, except for hyperglycemia or blood pressure, were reversed by olmesartan medoxomil. These results suggest that LV ANG II in SDT rats at 8 and 16 wk induces cardiomyocyte hypertrophy without affecting hyperglycemia or blood pressure, which promotes and suppresses coronary angiogenesis, respectively, via VEGF and thrombospondin-1 produced from hypertrophied cardiomyocytes under chronic hypoxia. Thrombospondin-1 may play an important role in the progression of diabetic cardiomyopathy in this model.
  • Naoko Otani, Tetsu Akimoto, Wako Yumura, Daisuke Matsubara, Yoshitaka Iwazu, Akihiko Numata, Takuya Miki, Fumi Takemoto, Noriyoshi Fukushima, Shigeaki Muto, Eiji Kusano
    DIAGNOSTIC PATHOLOGY 7 46  1746-1596 2012/04 [Refereed][Not invited]
    Glomerular crescents are most commonly associated with rapidly progressive crescentic glomerulonephritis; however, they also develop in response to a wide range of primary and secondary glomerular injuries. Since various kind of glomerulopathies occasionally overlay diabetic glomerular injuries, the presence of crescents in renal biopsy specimens of diabetics may have stimulated a search for etiologies other than diabetes. In this report, we describe an unusual case of diabetic glomerulosclerosis with peculiar extracapillary proliferation. Although such a relationship has so far been ignored in most of the literature, the etiological linkage between diabetic glomerulosclerosis and the development of crescents may not be exceptional. We have reviewed the previous literature and herein discuss the pathological implications of the development of crescents in patients with diabetic glomerulosclerosis. Virtual slides: The virtual slide(s) for this article can be found here:
  • Taro Sugase, Tetsu Akimoto, Yoshitaka Iwazu, Tomoyuki Yamazaki, Akihiko Numata, Fumi Takemoto, Shigeaki Muto, Eiji Kusano
    INTERNAL MEDICINE 51 (14) 1885 - 1888 0918-2918 2012 [Refereed][Not invited]
    A large number of renal biopsy studies have shown the concurrent presence of non-diabetic renal disease in diabetics. This report describes one such diabetic female patient with nephrotic syndrome due to minimal change glomerular disease who was successfully treated with prednisolone. Despite the remission of her nephrotic syndrome, she had gradual development of malignant ascites, which was finally interpreted to be linked to primary peritoneal carcinoma. It is necessary to bear in mind that malignancies may not only be the underlying etiology for paraneoplastic glomerular injuries, but also can be an independent pathogenic process, regardless of their nephrotic status during the overall management of the patients with ascites.
  • Takuya Miki, Tetsu Akimoto, Taro Sugase, Akihiko Numata, Naoko Otani, Yoshitaka Iwazu, Eri Takeshima, Yoshiyuki Morishita, Shigeaki Muto, Eiji Kusano
    INTERNAL MEDICINE 51 (24) 3395 - 3399 0918-2918 2012 [Refereed][Not invited]
    Rapidly progressive glomerulonephritis (RPGN) is characterized by the rapid deterioration of the renal function associated with crescent formation on renal biopsies. This report describes a case of RPGN caused by anti-glomerular basement membrane (GBM) glomerulonephritis in an elderly man with severe thrombocytopenia and a platelet count of 1.4x10(4)/mu L. Thrombotic microangiopathy (TMA) and heparin-induced thrombocytopenia (HIT) were implicated in the severe decrease in platelets. This report also discusses the pathological background and clinical management of TMA and HIT among patients with anti-GBM glomerulonephritis.
  • Kana Iwazu, Yoshitaka Iwazu, Shin-ichi Takeda, Tetsu Akimoto, Wako Yumura, Hideaki Takahashi, Chiharu Ito, Kuniyuki Kanai, Nobuyuki Taniguchi, Yoshikazu Hirai, Eiji Kusano
    INTERNAL MEDICINE 51 (21) 3051 - 3056 0918-2918 2012 [Refereed][Not invited]
    We herein present a case of serial opportunistic infections that included disseminated nocardiosis and cryptococcal meningitis in a 67-year-old man who was diagnosed with ANCA-associated vasculitis and treated with corticosteroids. Upon admission, the initial manifestations of the disease included subcutaneous tumors and multiple lesions in the brain and lungs. Nocardia farcinica was identified in a culture of the aspirated pus. The patient was successfully treated for disseminated nocardiosis with antibiotics. However, three months after discharge, he was hospitalized with complaints of nuchal pain. Cryptococcus neoformans was identified on a culture of the cerebrospinal fluid. Anti-fungal treatment resulted in the remission of cryptococcal meningitis.
  • Yoshitaka Iwazu, Shigeaki Muto, Ichiro Hirahara, Genro Fujisawa, Shin-ichi Takeda, Eiji Kusano
    JOURNAL OF HYPERTENSION 29 (12) 2440 - 2453 0263-6352 2011/12 [Refereed][Not invited]
    Objectives Excess mineralocorticoids such as deoxycorticosterone acetate (DOCA) together with salt are known to cause tubulointerstitial fibrosis, but the mechanisms underlying fibrosis progression are unclear. Therefore, we investigated the role of matrix metalloproteinase 2 (MMP2) in the epithelial-mesenchymal transition and fibrosis progression. Methods Uninephrectomized rats drank 0.9% NaCl and 0.3% KCl solution and were treated with DOCA alone, DOCA + spironolactone, or vehicle for 1, 4, or 8 weeks. SBP, kidney function and morphology, and kidney and urine MMP2 activity were compared among the groups. Results At week 4, the DOCA-treated group exhibited hypertension, tubulointerstitial fibrosis, increased MMP2 activity in the kidney and urine, and overexpression of MMP2 in proximal tubule cells and MMP14 in apical membranes; these results were more pronounced at week 8. At week 8, the proximal tubule cell apicolateral surface proteins villin, claudin 2, and E-cadherin were downregulated, and the mesenchymal marker a-smooth muscle actin was upregulated in the tubulointerstitium of DOCA-treated rats. These DOCA/salt-induced changes (except for hypertension) and fibrosis progression observed at week 8 were reversed by TISAM (a selective MMP2 inhibitor), which was administered from week 4 to week 8. All of the effects of DOCA/salt at week 8 were attenuated by spironolactone. Conclusion Eight weeks of treatment with DOCA/salt activated MMP2, primarily on the apical surface of proximal tubule cells, which induced epithelial-mesenchymal transition from the luminal side and promoted tubulointerstitial fibrosis progression. These MMP2-induced changes occurred via downstream processes regulated by mineralocorticoid receptors. J Hypertens 29: 2440-2453 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
  • Akihiko Numata, Tetsu Akimoto, Masaki Toshima, Yoshitaka Iwazu, Naoko Otani, Takuya Miki, Taro Sugase, Osamu Saito, Yoshitomo Hamano, Fumi Takemoto, Yoshihiko Ueda, Shigeaki Muto, Eiji Kusano
    CLINICAL AND EXPERIMENTAL NEPHROLOGY 15 (5) 769 - 773 1342-1751 2011/10 [Refereed][Not invited]
    In ordinary settings, human immunodeficiency virus (HIV)-associated nephropathy should be considered when HIV infection is associated with heavy proteinuria. On the other hand, hepatitis B virus (HBV) may also play a role in the development of glomerular injury among patients with HIV infection, since HIV and HBV infections commonly occur together due to shared modes of transmission. We present here a case of nephrotic syndrome in an HIV-positive patient complicated with HBV infection. A renal biopsy revealed sparse granular deposits of immunoglobulin G in the subepithelial region, consistent with membranous nephropathy (MN) stage I. Moreover, immunostaining exhibited weak anti-hepatitis B core activity within glomeruli. These results led us to consider that HBV-associated MN might play a role in the development of nephrotic syndrome. Although anti-viral treatment for patients with HBV-associated MN has been suggested to be clinically effective, the use of two anti-HIV agents (tenofovir and emtricitabine), both of which have anti-HBV activities, was not effective for the patient's nephrotic syndrome, despite obtaining a decrease in the serum HBV-DNA levels. A lack of prospective data suggests that many decisions on the treatment of glomerulopathies with HIV infections are potentially empirical. Obviously, further studies and accumulated clinical experience are required to better determine the pathogenesis and management of HBV-associated MN among patients with HIV infections.
  • Takahiro Masuda, Mitsunobu Murata, Sumiko Honma, Yoshitaka Iwazu, Nobuhiro Sasaki, Manabu Ogura, Akira Onishi, Yasuhiro Ando, Shigeaki Muto, Kazuyuki Shimada, Kazuomi Kario, Eiji Kusano, Yasushi Asano
    NEPHROLOGY DIALYSIS TRANSPLANTATION 26 (7) 2289 - 2295 0931-0509 2011/07 [Refereed][Not invited]
    Background. Sleep-disordered breathing (SDB), characterized by repetitive apnea and hypopnea during sleep, is a risk factor for cardiovascular disease. However, the links between SDB and cardiovascular events in hemodialysis (HD) patients have not been clearly evaluated. Methods. We followed the clinical outcome of 94 HD patients, who underwent overnight pulse oximetry on dialysis day. The SDB group was defined as 3% oxygen desaturation index (ODI) over five events per hour, and the others were the normal group. The primary outcome was cardiovascular events and death. We used Kaplan-Meier curve and Cox proportional hazard model for survival analyses. Results. Forty-four patients (46.8%) were classified into the SDB group. Body mass index, diabetes mellitus, 3% ODI and Epworth sleepiness scale were significantly higher, and duration of dialysis, Kt/V, normalized protein catabolism rate and hemoglobin were lower in the SDB group than in the normal group. During a median 55 months of follow-up, Kaplan-Meier analysis revealed that the SDB group had a significantly higher rate of cardiovascular events and all-cause mortality than the normal group. Age, cardiothoracic ratio, serum albumin and 3% ODI were predictors of cardiovascular events and all-cause mortality at univariate Cox regression analysis. In the adjusted analysis, SDB is an independent predictor of increased cardiovascular events (hazard ratio 3.10; 95% confidence interval (CI), 1.35-7.12; P = 0.008) and all-cause mortality (hazard ratio 2.81; 95% CI, 1.07-7.41; P = 0.037). Conclusions. SDB is an independent risk factor for cardiovascular events and mortality in HD patients. Effective and earlier treatment for these patients is needed to improve clinical outcome.
  • Yoshitaka Iwazu, Tetsu Akimoto, Shigeaki Muto, Eiji Kusano
    CLINICAL AND EXPERIMENTAL NEPHROLOGY 15 (1) 132 - 135 1342-1751 2011/02 [Refereed][Not invited]
    We herein describe an adult male patient who presented with tonsillitis, purpura, hematuria, and proteinuria. The serological analyses revealed elevated serum antistreptolysin, and the throat culture yielded Lancefield group A beta-hemolytic streptococci. A renal biopsy revealed mild mesangial proliferation associated with granular mesangial depositions of IgA and C3, consistent with Henoch-Schonlein purpura nephritis (HSPN). Initially, the patient was treated with dipyridamole, which was followed by limited improvements in the proteinuria and hematuria. Nine months later, the tonsillitis relapsed due to GAS infection and deteriorated urinary abnormalities were noticed, which finally disappeared after monotherapeutic tonsillectomy. Although the impact of tonsillectomy on the treatment of HSPN remains to be characterized, our observations suggest that tonsillectomy in the present patient played a pivotal role in facilitating the recovery of the renal injuries. Because the arbitrary application of a tonsillectomy appears to be accompanied by ethical concerns, the evaluation of the clinical benefits of this procedure should be addressed more directly in the future.
  • Akiko Hashimoto, Yoshitaka Iwazu, Yasuhiro Ando, Makoto Inoue, Osamu Saito, Shinji Asakura, Shigeaki Muto, Takashi Yagisawa, Eiji Kusano
    Japanese Journal of Nephrology 53 (7) 1034 - 1040 0385-2385 2011 [Refereed][Not invited]
    The patient was a 53-year-old woman who had bilateral renal arterial constriction due to Takayasu's arteritis, and developed end-stage renal failure. When transient loss of consciousness occurred in 2002, she was diagnosed with subclavian steal syndrome (SSS). The renal failure worsened in June 2004, and there was concern that the left SSS could become aggravated as a consequence of creating an arterio-venous (AV) shunt. Although peritoneal dialysis was strongly recommended, she elected to undergo hemodialysis. We confirmed that there was no reduction of cerebral blood flow using brain single photon emission computed tomography (SPECT). Right and left examinations indicated the site at which an AV shunt should be created and subsequently, the AV shunt was created on the left fore-arm. Brain SPECT findings were again confirmed after dialysis, at the time of hemodialysis induction, and again 2 years after hemodialysis induction, showing no reduction in cerebral blood flow. She has no apparent symptoms or signs of left SSS, to date. Although it is known that an SSS could arise after AV shunt creation, there has been no report of the creation of an AV shunt in a case of SSS. The present case suggests that cerebral blood flow measurement using brain SPECT is useful for evaluating cerebral hemodynamics before AV fistula creation among patients with Takayasu's arteritis.
  • Takahiro Masuda, Mitsunobu Murata, Sumiko Honma, Yoshitaka Iwazu, Manabu Ogura, Akira Onishi, Kazuyuki Shimada, Eiji Kusano, Yasushi Asano
    NDT Plus 1 (5) 378 - 379 1753-0784 2008/10 [Refereed][Not invited]
  • Yoshitaka Iwazu, Shigeaki Muto, Genro Fujisawa, Eiko Nakazawa, Koji Okada, Shun Ishibashi, Eiji Kusano
    HYPERTENSION 51 (3) 749 - 754 0194-911X 2008/03 [Refereed][Not invited]
    We examined whether and how peritubular capillary (PTC) loss in the renal cortex contributes to the development of deoxycorticosterone acetate (DOCA)/salt-induced tubulointerstitial fibrosis. Uninephrectomized rats provided with 0.9% NaCl/0.3% KCl drinking solution ad libitum were divided into control, DOCA, and spironolactone groups, which were administered vehicle, DOCA alone, and DOCA plus spironolactone for 1 (initial phase) and 4 weeks (delayed phase), respectively. Exposure to DOCA initiated a sequence of events that initially involved reduced PTC density, followed by a delayed response that involved further reduced PTC density, development of tubulointerstitial fibrosis and hypertension, enhanced expression of transforming growth factor-beta 1 and connective tissue growth factor, and impaired renal function. Concomitant with the reduced PTC density, the 2 hypoxia-responsive angiogenic factors (vascular endothelial growth factor and hypoxia-inducible factor-1 alpha) and the antiangiogenic factor (thrombospondin-1) were upregulated in cortical tubular cells of the DOCA group during the 2 phases and only in the delayed phase, respectively. In the DOCA group, PTC endothelial cell apoptosis was enhanced during the 2 phases, and PTC endothelial cell proliferation was inhibited in the delayed phase. In accordance with upregulation of thrombospondin-1, p53 expression was enhanced in the DOCA group in the delayed phase. The initial and delayed effects of DOCA were blocked in the spironolactone group. We conclude that exposure to DOCA initially caused the reduced PTC density associated with enhanced apoptosis independent of thrombospondin-1, which induced tubulointerstitial fibrosis via p53-mediated thrombospondin-1 activation, and spironolactone conversely corrected the effects of DOCA to prevent fibrosis.
  • Iwazu Y, Muto S, Fujisawa G, Okada K, Nakazawa E, Ishibashi S, Kusano E
    Hypertension 51 (3) 749 - 754 2008 [Refereed][Not invited]
  • Yoshitaka Iwazu, Sumiko Honma, Genro Fujisawa, Kiyoko Uki, Ichiro Yanaka, Yoshiaki Sato, Mitsunobu Murata, Eiji Kusano, Yasushi Asano
    Clinical and Experimental Nephrology 11 (3) 230 - 234 1342-1751 2007/09 [Refereed][Not invited]
    A 66-year-old woman was admitted to our hospital because of vomiting and appetite loss. For the 2 days prior to admission, she had a cold, which had developed into acute viral bronchitis on admission. Because laboratory data on admission showed hyponatremia, intravenous infusion of Ringer's lactate solution was started. However, generalized seizures appeared, and she developed a coma on the day of admission. Her plasma antidiuretic hormone (ADH) level was high in the context of a low serum osmolality on the second hospital day. The infusion rate was increased, and the patient's consciousness level returned to normal. However, her normalized serum Na level declined again as she drank much water to reduce throat discomfort. As the throat discomfort caused by the throat inflammation improved with azulene gargling, her water intake was reduced, and the serum Na concentration returned to normal. Thus, polydipsia caused by a throat inflammation partially contributed to hyponatremia in this patient. We note that increased ADH secretion has been reported in adults with acute respiratory infection. Therefore, we concluded that polydipsia caused by the throat inflammation, plus increased ADH secretion, resulted in hyponatremia in this patient. We should pay attention to the behavior of drinking extra fluid in patients with acute respiratory infections. © 2007 Japanese Society of Nephrology.
  • Miyazaki K, Iwazu Y, Saito O, Hashimoto A, Katsuki T, Shimada K, Hishida R, Nakano I, Muto S, Kusano E
    Nihon Naika Gakkai zasshi. The Journal of the Japanese Society of Internal Medicine 95 (5) 942 - 944 0021-5384 2006/05 [Refereed][Not invited]
  • Yoshitaka Iwazu, Sumiko Honma, Seiji Minota, Yasushi Asano, Eiji Kusano
    Japanese Journal of Nephrology 48 (4) 345 - 353 0385-2385 2006 [Refereed][Not invited]
    There have been numerous studies on elder-onset systemic lupus erythematosus, but few on elder-onset lupus nephritis. Many studies have shown that the severity of systemic lupus erythematosus declines with the advance of age. We retrospectively studied the clinical characteristics and prognosis of a Japanese lupus nephritis population to review the behavior of 12 elder-onset patients whose onset of disease, defined as the initial manifestation of systemic lupus erythematosus, occurred after the age of 50 years. Data on the clinical features and laboratory findings of 37 patients with lupus nephritis were collected. Elder-onset patients tended to have a decreased incidence of class V histology and an increased incidence of class II histology compared with younger-onset patients. The incidences of nephrotic syndrome, renal failure and class IV histology as well as the requirements of immunosuppressive therapies were similar in the two groups. In the intensive therapy (IV methylprednisolone, plasmapheresis and their combination) group, elder-onset patients had a higher mortality rate. In this study, elder-onset lupus nephritis patients did not belong to a benign subgroup of the lupus nephritis population, and it was found that intensive therapy of elder-onset patients potentially increased the risk of death.
  • Iwazu Y, Shimazaki H, Sawada M, Morita M, Kawakami T, Takiyama Y, Fujimoto K, Nakano I
    Nihon Naika Gakkai zasshi. The Journal of the Japanese Society of Internal Medicine 91 (8) 2466 - 2468 0021-5384 2002/08 [Refereed][Not invited]

Conference Activities & Talks

  • The Endothelial Progenitor Cell (EPC) Migration Inhibitor FTY720 Auguments Malignant Nephrosclerosis in Deoxycorticosterone Acetate (DOCA)/Salt Hypertension Rats.  [Not invited]
    IWAZU Yoshitaka
    The 45th Annual Meeting of the American Society of Nephrology  2012/10
  • TISAM, a selective Matrix Metalloproteinase (MMP)-2 Inhibitor, prevents progression of deoxycorticosterone acetate (DOCA) / salt-induced tubulointerstitial fibrosis.  [Not invited]
    IWAZU Yoshitaka
    The 42th Annual Meeting of the American Society of Nephrology  2009
  • Matrix metalloproteinase (MMP)-2 induces tubular epithelial cell injury from the urine space and develops deoxycorticosterone acetate (DOCA) / salt-induced tubulointerstitial fibrosis.  [Not invited]
    IWAZU Yoshitaka
    The 40th Annual Meeting of the American Society of Nephrology  2007
  • Urinary matrix metalloproteinase (MMP)-2 is a useful marker for the development of deoxycorticosterone acetate (DOCA) / salt-induced tubulointerstitial fibrosis.  [Not invited]
    IWAZU Yoshitaka
    The 39th Annual Meeting of the American Society of Nephrology  2006
  • The reduced peritubular capillary (PTC) density associated with renal hypertrophy contributes to the development of deoxycorticosterone acetate (DOCA) / salt-induced tubulointerstitial fibrosis.  [Not invited]
    IWAZU Yoshitaka
    The 39th Annual Meeting of the American Society of Nephrology  2006
  • Mineralocorticoid nuclear receptor (MR) antagonist spironolactone (SPL) prevents mineralocorticoid/salt-induced renal injury via inhibition of tubulointerstitial hypoxia.  [Not invited]
    IWAZU Yoshitaka
    The 38th Annual Meeting of the American Society of Nephrology  2005

Research Grants & Projects

  • ミネラルコルチコイドと食塩による腎障害(特に尿細管間質)の機序の解明
    Date (from‐to) : 2004

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