Izumi Amano
Tenri Hospital
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Publication
Featured researches published by Izumi Amano.
Therapeutic Apheresis and Dialysis | 2006
Kazutaka Kukita; Seiji Ohira; Izumi Amano; Hidemune Naito; Nakanobu Azuma; Kiyoshi Ikeda; Yutaka Kanno; Takashi Satou; Shinji Sakai; Tokuichiro Sugimoto; Yoshiaki Takemoto; Hiroaki Haruguchi; Jun Minakuchi; Akira Miyata; Noriyoshi Murotani; Hideki Hirakata; Tadashi Tomo; Tadao Akizawa
Abstract: The guideline committee of Japanese Society for Dialysis Therapy (JSDT), chaired by Dr Ohira, has published an original Japanese guideline, ‘Guidelines for Vascular Access Construction and Repair for Chronic Hemodialysis’. The guideline was created mainly because of the existence of numerous factors characteristic of Japanese hemodialysis therapy, which are described in this report, and because we recognized the necessity for standardization in vascular access‐related surgeries. This guideline consists of 10 chapters, each of which includes guidelines, explanations or comments and references. The first chapter discusses informed consent of vascular access (VA)‐related surgeries, which often resulted in trouble between dialysis staff and patients. The second chapter describes the fundamentals of VA construction and timing of the introduction of hemodialysis with emphasis on the avoidance of catheter indwelling if at all possible. In the third chapter, arteriovenous fistula (AVF) construction and management are discussed from the viewpoint of the most preferable type of VA. The fourth chapter deals with arteriovenous grafts (AVG) which has recently increased in clinical applications. The factors which improve the AVG patency rate are discussed and postoperative management methods are emphasized to avoid possible complications. The fifth chapter deals with short and long‐term vascular catheters. It is emphasized that these methods are definitely effective but, at the same time, are apt to be associated with several serious complications and might result in vascular damage. In the sixth chapter, superficialization of an artery is explained. This was originally for emergency use or backup but has been used permanently in 2–3% of Japanese hemodialysis patients. In the seventh chapter, methods for the use of VA are described and the buttonhole method is referred to as one of the options for patients who complain of intense pain at every cannulation. In the eighth chapter, the importance of continuous monitoring is stressed for maintaining appropriate function of VA. As a rule, the internal shunt type VA (AVF, AVG) places a burden on cardiac function. Thus, in the ninth chapter, it is stressed that VA construction, maintenance and repair should always be carried out with consideration of cardiac function which is not constant but variable. The 10th chapter forms one of the cores of this guideline and deals with repair and timing of VA. It is shown how to select a surgical or interventional repair method. In the final 11th chapter, VA types and resultant morbidity and mortality of hemodialysis patients are reviewed.
American Journal of Nephrology | 2000
Yoshihiro Matsumoto; Motoyoshi Sato; Hiroshige Ohashi; Hajime Araki; Mitsunobu Tadokoro; Yukio Osumi; Hiroyasu Ito; Hiroyuki Morita; Izumi Amano
Cardiac diseases are well known among patients on maintenance hemodialysis (HD), and carnitine deficiency may be an important factor in cardiac morbidity. We studied the effects of low-dose L-carnitine treatment (500 mg/day) on chest symptoms (dyspnea on exertion, chest pain, palpitation), cardiac function, and left ventricular (LV) mass in 9 HD patients with reduced ejection fraction (EF). After 6 months of L-carnitine treatment, most patients had at least some improvement in chest symptoms, while LVEF was increased and LV mass was decreased. Carnitine fractions increased and reached plateaus at 2–3 times the baseline levels. These results suggest that prolonged low-dose L-carnitine treatment can improve the cardiac morbidity by restoring decreased carnitine tissue levels and impaired oxidation of FFA.
Blood Purification | 2001
Yoshihiro Matsumoto; Izumi Amano; Shinichi Hirose; Yoshinari Tsuruta; Shigeko Hara; Michio Murata; Tsuneki Imai
While renal anemia can be successfully treated by use of erythropoietin (EPO) in most hemodialysis (HD) patients, some patients have anemia that is refractory to treatment with a high dose of EPO. We examined whether L-carnitine treatment could raise hematocrit (Hct) levels in such patients. Fourteen HD patients who showed a poor response to EPO and no evident factors which inhibit a response to EPO were selected to receive oral L-carnitine (500 mg/day) in a 3-month trial. During the study, 36% of the patients showed Hct increases of more than 2%. Statistical analysis revealed significant increases of Hct (p = 0.003) and total iron-binding capacity (TIBC) (p = 0.050) and a significant decrease of ferritin (p = 0.005). In addition, we found that red blood cells (RBCs) in HD patients contained a comparable level of carnitine to normal controls, despite the presence of serum carnitine deficiency, and that RBC carnitine was not removed through HD, in contrast to serum carnitine. These results suggest that RBC carnitine may be essential for RBCs to perform their metabolic function in renal anemia and that oral L-carnitine treatment could improve anemia in poor responders to EPO.
Therapeutic Apheresis and Dialysis | 2015
Kazutaka Kukita; Seiji Ohira; Izumi Amano; Hidemune Naito; Nakanobu Azuma; Kiyoshi Ikeda; Yutaka Kanno; Takashi Satou; Shinji Sakai; Tokuichiro Sugimoto; Yoshiaki Takemoto; Hiroaki Haruguchi; Jun Minakuchi; Akira Miyata; Noriyoshi Murotani; Hideki Hirakata; Tadashi Tomo; Tadao Akizawa
Abstract: The guideline committee of Japanese Society for Dialysis Therapy (JSDT), chaired by Dr Ohira, has published an original Japanese guideline, ‘Guidelines for Vascular Access Construction and Repair for Chronic Hemodialysis’. The guideline was created mainly because of the existence of numerous factors characteristic of Japanese hemodialysis therapy, which are described in this report, and because we recognized the necessity for standardization in vascular access-related surgeries. This guideline consists of 10 chapters, each of which includes guidelines, explanations or comments and references. The first chapter discusses informed consent of vascular access (VA)-related surgeries, which often resulted in trouble between dialysis staff and patients. The second chapter describes the fundamentals of VA construction and timing of the introduction of hemodialysis with emphasis on the avoidance of catheter indwelling if at all possible. In the third chapter, arteriovenous fistula (AVF) construction and management are discussed from the viewpoint of the most preferable type of VA. The fourth chapter deals with arteriovenous grafts (AVG) which has recently increased in clinical applications. The factors which improve the AVG patency rate are discussed and postoperative management methods are emphasized to avoid possible complications. The fifth chapter deals with short and long-term vascular catheters. It is emphasized that these methods are definitely effective but, at the same time, are apt to be associated with several serious complications and might result in vascular damage. In the sixth chapter, superficialization of an artery is explained. This was originally for emergency use or backup but has been used permanently in 2–3% of Japanese hemodialysis patients. In the seventh chapter, methods for the use of VA are described and the buttonhole method is referred to as one of the options for patients who complain of intense pain at every cannulation. In the eighth chapter, the importance of continuous monitoring is stressed for maintaining appropriate function of VA. As a rule, the internal shunt type VA (AVF, AVG) places a burden on cardiac function. Thus, in the ninth chapter, it is stressed that VA construction, maintenance and repair should always be carried out with consideration of cardiac function which is not constant but variable. The 10th chapter forms one of the cores of this guideline and deals with repair and timing of VA. It is shown how to select a surgical or interventional repair method. In the final 11th chapter, VA types and resultant morbidity and mortality of hemodialysis patients are reviewed.
Therapeutic Apheresis and Dialysis | 2003
Motoyoshi Sato; Izumi Amano
Abstract: Low‐density lipoprotein apheresis (LDLA) leads to an improvement of microcirculation during the very early stages of treatment, and continued treatment may produce antiatherogenic effects in patients with peripheral arterial disease (PAD). Suppression of oxidative stress, improvement of endothelial functions and alteration in the action of vasoactive compounds may occur with the improvement of the rheological property of blood as a result of aggressive removal of atherogenic factors including LDL, possibly resulting in the suppression of development of atherosclerosis. As these effects of LDLA may ameliorate not only PAD but also ischemia in other organs, it is suggested that repeated LDLA prevents the progression of atherosclerotic diseases and probably improves the long‐term prognosis of patients with PAD.
Therapeutic Apheresis and Dialysis | 2013
Fumitake Gejyo; Izumi Amano; Tetsuo Ando; Mari Ishida; Seiichi Obayashi; Hiroshi Ogawa; Toshihiko Ono; Yutaka Kanno; Tateki Kitaoka; Kazutaka Kukita; Satoshi Kurihara; Motoyoshi Sato; Jeongsoo Shin; Masashi Suzuki; Susumu Takahashi; Yoshio Taguma; Yoshiaki Takemoto; Ryoichi Nakazawa; Takeshi Nakanishi; Hidetoshi Nakamura; Shigeko Hara; Makoto Hiramatsu; Ryuichi Furuya; Ikuto Masakane; Kenji Tsuchida; Yasuki Motomiya; Hiroyuki Morita; Kunihiro Yamagata; Kunihiko Yoshiya; Tomoyuki Yamakawa
Dialysis‐related amyloidosis is a serious complication of long‐term hemodialysis. Its pathogenic mechanism involves accumulation of β2‐microglobulin in the blood, which then forms amyloid fibrils and is deposited in tissues, leading to inflammation and activation of osteoclasts. Lixelle, a direct hemoperfusion column for adsorption of β2‐microglobulin, has been available since 1996 to treat dialysis‐related amyloidosis in Japan. However, previous studies showing the therapeutic efficacy of Lixelle were conducted in small numbers of patients with specific dialysis methods. Here, we report the results of a nationwide questionnaire survey on the therapeutic effects of Lixelle. Questionnaires to patients and their attending physicians on changes in symptoms of dialysis‐related amyloidosis by Lixelle treatment were sent to 928 institutions that had used Lixelle, and fully completed questionnaires were returned from 345 patients at 138 institutions. The patients included 161 males and 184 females 62.9 ± 7.7 years age, who had undergone dialysis for 25.9 ± 6.2 years and Lixelle treatment for 3.5 ± 2.7 years. Based on self‐evaluation by patients, worsening of symptoms was inhibited in 84.9–96.5% of patients. Of the patients, 91.3% felt that worsening of their overall symptoms had been inhibited, while attending physicians evaluated the treatment as effective or partially effective for 72.8% of patients. Our survey showed that Lixelle treatment improved symptoms or prevented the progression of dialysis‐related amyloidosis in most patients.
Asaio Journal | 1993
Yutaka Inagaki; Izumi Amano; Toshihiko Otsu
Twenty-nine cases of hypoglycemia induced by disopyramide (DP) have been reported in the literature to date. Twenty of the reported cases showed hypo-renal function and a high concentration was rare. DP is metabolized to mono-N-dealkyldisopyramide (MND) in the liver and accumulation of MND is to be expected in renal failure. Both DP and MND bind mainly to alpha-1-acid glycoprotein (AAG) in the plasma. In 10 hemodialysis (HD) patients with normal liver function receiving DP therapy in the steady state. DP, MND and AAG were measured pre- and post-HD. Ten patients with normal renal and liver function were selected as the controls. The DP concentration was 2.08 +/- 0.39 micrograms/ml (mean +/- SD) in the control group, and the pre- and post-HD levels were 2.40 +/- 1.08 micrograms/ml and 1.73 +/- 0.87 micrograms/ml, respectively, in the HD group. The MND concentration was 0.42 +/- 0.23 micrograms/ml in the controls, 1.53 +/- 0.52 micrograms/ml in pre-HD and 1.08 +/- 0.32 micrograms/ml in post-HD. Although DP and MND are both classified as substances of small molecular weight, the average decrease in plasma concentration from pre- to post-HD was under 30% with both agents. The MND/DP ratio in the HD group was higher than in the controls, but there was no significant difference between pre- and post-HD. The AAG level was 75 +/- 5mg/dl in the controls and 109 +/- 11mg/dl before HD in the HD group (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Therapeutic Apheresis and Dialysis | 2006
Izumi Amano; Seiji Ohira; Yasuo Goto; Ichiro Hino; Kiyosi Ikeda; Kazutaka Kukita; Hiroaki Haruguchi
Abstract: In cases of vascular access (VA) for hemodialysis including arteriovenous fistula and arteriovenous graft, venipuncture and hemostasis are usually repeated three times a week. Accordingly, it is assumed that VA vascular disorders are worsened following long‐term hemodialysis. In particular, angiostenosis frequently occurs and results in insufficient blood flow or increased venous pressure. Additionally, stenosis is a major cause of VA occlusion. While VA intervention treatment is mainstream for VA stenosis, its major advantage lies in its less invasiveness because it is a percutaneous treatment. A further advantage of this treatment procedure is that the existing VA can be preserved intact. For practical use of VA intervention treatment, however, compliance with the therapeutic indication guideline is required. In K/DOQI of the United States, such a guideline has already been formulated based on evidence and specialist opinion, while the guideline of the European Vascular Access Society is presented in the form of a flowchart. The Japanese Society for Dialysis Therapy is currently preparing a guideline for the construction and maintenance of VA, which introduces the timing and principles of repair of VA in the following six categories: (i) stenosis; (ii) occlusion; (iii) venous hypertension; (iv) steal syndrome; (v) excess blood flow; and (vi) infection. Except for infection, most of the treatments for these events involve VA intervention, thus the need for the guideline for VA intervention treatment is becoming widely recognized.
Nephron | 2000
Yoshihiro Matsumoto; Izumi Amano
Accessible online at: www.karger.com/journals/nef Dear Sir, Idiopathic membranous nephropathy (IMN) is a common cause of nephrotic syndrome in adults. Several regimens, including glucocorticoids, immunosuppressive drugs, or both, have been used for more than 30 years, but their efficacy remains in doubt. Cattran et al. [1] suggested that prednisone should not be used in the treatment of IMN, and Schieppati et al. [2] concluded that symptomatic treatment is best for most patients with IMN. However, the course of the disorder can result in renal failure in some patients, especially in those with a poor prognosis (those with sustained nephrotic syndrome or progressive loss of renal function). Thus, new drugs or regimens are expected to be found. We performed a study using a newly developed immunosuppressant, mizoribine, in combination with prednisone. Mizoribine, which inhibits purine nucleoside synthesis [3], is in use for renal transplant patients in Japan because of its lesser side effects and its potency comparable to that of azathioprine. The steroid-sparing effect of mizoribine has also been reported in children with long-term nephrotic syndrome [4]. We recently investigated whether mizoribine is effective for the treatment of IMN. Four patients (50–72 years of age) who had membranous nephropathy diagnosed by reFig. 1. Effect of treatment with mizoribine and prednisone on proteinuria in 4 patients with IMN.
Renal Failure | 2006
Hidemasa Miyauchi; Yoshihiro Matsumoto; Arao Futenma; Izumi Amano; Junichiro Miyauchi; Seiichi Matsuo
Arrhythmia is known to cause sudden death in hemodialysis patients. Heparin administration releases lipoprotein lipase from the capillary endothelial cell surface, resulting in an increase in the plasma levels of free fatty acids; higher levels of free fatty acids may affect the occurrence of arrhythmias. This study assessed whether the occurrence of arrhythmias during hemodialysis could be suppressed by replacing unfractionated heparin with low molecular weight heparin. Ten dialysis patients who had supraventricular premature contraction and/or ventricular premature contraction were monitored by the Holter electrocardiograph system during hemodialysis. To investigate the effect of each form of heparin on plasma lipid metabolism, the lipoprotein lipase and lipid levels before and during hemodialysis were measured. The occurrence of arrhythmias was significantly suppressed in hemodialysis using low molecular weight heparin, as compared with hemodialysis using unfractionated heparin. Lower lipoprotein lipase and free fatty acids levels were also observed in hemodialysis using low molecular weight heparin. The authors concluded that hemodialysis using low molecular weight heparin instead of unfractionated heparin could be effective in protecting hemodialysis patients with arrhythmias against arrhythmia-related cardiac events.