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Dive into the research topics where Ryuji Fukazawa is active.

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Featured researches published by Ryuji Fukazawa.


The Lancet | 2012

Efficacy of immunoglobulin plus prednisolone for prevention of coronary artery abnormalities in severe Kawasaki disease (RAISE study): a randomised, open-label, blinded-endpoints trial

Tohru Kobayashi; Tsutomu Saji; Tetsuya Otani; Kazuo Takeuchi; Tetsuya Nakamura; Hirokazu Arakawa; Taichi Kato; Toshiro Hara; Kenji Hamaoka; Shunichi Ogawa; Masaru Miura; Yuichi Nomura; Shigeto Fuse; Fukiko Ichida; Mitsuru Seki; Ryuji Fukazawa; Chitose Ogawa; Kenji Furuno; Hirohide Tokunaga; Shinichi Takatsuki; Shinya Hara; Akihiro Morikawa

BACKGROUNDnEvidence indicates that corticosteroid therapy might be beneficial for the primary treatment of severe Kawasaki disease. We assessed whether addition of prednisolone to intravenous immunoglobulin with aspirin would reduce the incidence of coronary artery abnormalities in patients with severe Kawasaki disease.nnnMETHODSnWe did a multicentre, prospective, randomised, open-label, blinded-endpoints trial at 74 hospitals in Japan between Sept 29, 2008, and Dec 2, 2010. Patients with severe Kawasaki disease were randomly assigned by a minimisation method to receive either intravenous immunoglobulin (2 g/kg for 24 h and aspirin 30 mg/kg per day) or intravenous immunoglobulin plus prednisolone (the same intravenous immunoglobulin regimen as the intravenous immunoglobulin group plus prednisolone 2 mg/kg per day given over 15 days after concentrations of C-reactive protein normalised). Patients and treating physicians were unmasked to group allocation. The primary endpoint was incidence of coronary artery abnormalities during the study period. Analysis was by intention to treat. This trial is registered with the University Hospital Medical Information Network clinical trials registry, number UMIN000000940.nnnFINDINGSnWe randomly assigned 125 patients to the intravenous immunoglobulin plus prednisolone group and 123 to the intravenous immunoglobulin group. Incidence of coronary artery abnormalities was significantly lower in the intravenous immunoglobulin plus prednisolone group than in the intravenous immunoglobulin group during the study period (four patients [3%] vs 28 patients [23%]; risk difference 0·20, 95% CI 0·12-0·28, p<0·0001). Serious adverse events were similar between both groups: two patients had high total cholesterol and one neutropenia in the intravenous immunoglobulin plus prednisolone group, and one had high total cholesterol and another non-occlusive thrombus in the intravenous immunoglobulin group.nnnINTERPRETATIONnAddition of prednisolone to the standard regimen of intravenous immunoglobulin improves coronary artery outcomes in patients with severe Kawasaki disease in Japan. Further study of intensified primary treatment for this disease in a mixed ethnic population is warranted.nnnFUNDINGnJapanese Ministry of Health, Labour and Welfare.


Pediatrics International | 2007

Stromal cell‐derived factor‐1α improves infarcted heart function through angiogenesis in mice

Takashi Sasaki; Ryuji Fukazawa; Shunichi Ogawa; Shigeto Kanno; Takashi Nitta; Masami Ochi; Kazuo Shimizu

Background: Local delivery of stromal cell‐derived factor‐1α (SDF‐1) has been demonstrated to improve hind limb ischemia through enhanced neovascularization in animals. It was hypothesized that local administration of SDF‐1 also contributes to neovascularization of ischemic heart.


Circulation | 1997

Silent Myocardial ischemia in Kawasaki disease : Evaluation of percutaneous transluminal coronary angioplasty by dobutamine stress testing

Shunichi Ogawa; Ryuji Fukazawa; Takashi Ohkubo; Jiakun Zhang; Nobuyuki Takechi; Yukio Kuramochi; Yoshiaki Hino; Osamu Jimbo; Yasuhiro Katsube; Mitsuhiro Kamisago; Yukiko Genma; Masao Yamamoto

BACKGROUNDnMyocardial ischemia and myocardial infarction are the most serious complications of coronary artery lesions in children with Kawasaki disease (KD). Therefore, early detection and treatment of myocardial ischemia in patients with KD is essential. We studied the effectiveness of percutaneous transluminal coronary angioplasty (PTCA) in patients with silent myocardial ischemia detected by dobutamine stress 99mTc myocardial scintigraphy (TMS), body surface mapping (BMS), and signal-averaged ECG late potentials (ELP).nnnMETHODS AND RESULTSnEight of 76 asymptomatic patients with a coronary stenosis >25% and a positive dobutamine stress test were considered to have silent myocardial ischemia. All eight patients had >95% stenoses demonstrated by coronary angiography (CAG) just before PTCA. After PTCA, CAG showed that all of the coronary artery stenoses had been reduced to <50%. Additionally, intravascular ultrasonography (IVUS) performed in five patients before and after PTCA demonstrated adequate dilation of the coronary stenosis after PTCA. All eight patients underwent dobutamine stress TMS, BMS, and ELP 2 to 3 months after PTCA, which demonstrated no regions of myocardial ischemia. Approximately 6 months later, CAG was performed in all eight patients, and only one patient had developed restenosis.nnnCONCLUSIONSnPTCA effectively dilates stenotic coronary arteries in children with KD. Moreover, dobutamine stress TMS, BMS, and ELP are useful for detecting silent myocardial ischemia and estimating the effectiveness of PTCA. Furthermore, IVUS is useful for evaluating the severity of coronary artery lesions before and after PTCA in patients with KD.


Pediatrics International | 2007

Reduced shear stress and disturbed flow may lead to coronary aneurysm and thrombus formations

Takashi Ohkubo; Ryuji Fukazawa; Ei Ikegami; Shunichi Ogawa

Background: With Kawasaki disease it is important to clarify the mechanisms of coronary artery aneurysm and thrombus to avoid acute myocardial infarction. The authors tested the hypothesis that shear stress is reduced at coronary branching sites and in coronary artery aneurysms, and that this reduction of shear stress can promote formation of coronary artery aneurysms and thrombus.


American Journal of Cardiology | 1996

Evaluation of myocardial ischemia and infarction by signal-averaged electrocardiographic late potentials in children with Kawasaki disease

Shunichi Ogawa; Yuichi Nagai; Jiakun Zhang; Kunio Yuge; Yoshiaki Hino; Osamu Jimbo; Ryuji Fukazawa; Riku Hayashi; Mitsuhiro Kamisago; Takashi Seki; Yukiko Genma; Takashi Ohkubo; Nobuyuki Takechi; Masao Yamamoto

We investigated myocardial ischemia and old myocardial infarction noninvasively using signal-averaged electrocardiographic late potentials (LPs) in patients with Kawasaki disease. Patients were divided into 4 groups: a noncoronary artery lesion group (n=136), a coronary artery lesion group (without myocardial ischemia and an old myocardial infarction; n=33), an ischemia group (n=16), and an old myocardial infarction group (n=13). Grouping was based on exercise thallium-201 myocardial scintigraphy, thallium-201 myocardial scintigraphy, exercise electrocardiography, coronary angiography, left ventriculography, and echocardiography. Signal-averaged electrocardiograms were recorded using a high-resolution system. Values of filtered QRS duration (f-QRSd), root-mean-square voltage, and duration of low-amplitude signal were judged using our own body surface area-related criteria (n=205) to determine positive rates of LPs and sensitivities and specificities to ischemia and infarction. These data were also interpreted using published criteria for adults and compared with those interpreted by our criteria. Positive rates by our criteria were 0% in the noncoronary artery lesion group, 9.1% in the coronary lesion group, 56.3% in the ischemia group, and 69.2% in the old myocardial infarction group. However, using the criteria for adults, these values were 0%, 3.0%, 25%, and 46.2%, respectively. Sensitivities to ischemia and infarction using our criteria were significantly higher (56.3% and 69.2%) than those using the criteria for adults (p < 0.05). Moreover, specificities to ischemia and infarction were very high (93.4% and 93.5%, respectively) using our criteria, and there were no significant differences from specificities using the criteria for adults. Also, we examined the reproducibility of values of LPs and LP parameters. The values of filtered QRS duration showed a high reproducibility in both LP-positive and -negative groups, followed by low-amplitude signal and then root-mean-square voltage. The results of LP presence or absence showed 100% reproducibility for both the LP-positive and -negative groups, supporting the utility of LPs for clinical applications. Thus, LPs provide useful information in a noninvasive manner for clarifying ischemia and infarction in patients with Kawasaki disease.


PLOS ONE | 2016

Variations in ORAI1 Gene Associated with Kawasaki Disease

Yoshihiro Onouchi; Ryuji Fukazawa; Kenichiro Yamamura; Hiroyuki Suzuki; Nobuyuki Kakimoto; Tomohiro Suenaga; Takashi Takeuchi; Hiromichi Hamada; Takafumi Honda; Kumi Yasukawa; Masaru Terai; Ryota Ebata; Kouji Higashi; Tsutomu Saji; Shinichi Takatsuki; Kazunobu Ouchi; Fumio Kishi; Tetsushi Yoshikawa; Toshiro Nagai; Kunihiro Hamamoto; Yoshitake Sato; Akihito Honda; Hironobu Kobayashi; Junichi Sato; Shoichi Shibuta; Masakazu Miyawaki; Ko Oishi; Hironobu Yamaga; Noriyuki Aoyagi; Megumi Yoshiyama

Kawasaki disease (KD; MIM#61175) is a systemic vasculitis syndrome with unknown etiology which predominantly affects infants and children. Recent findings of susceptibility genes for KD suggest possible involvement of the Ca(2+)/NFAT pathway in the pathogenesis of KD. ORAI1 is a Ca(2+) release activated Ca(2+) (CRAC) channel mediating store-operated Ca(2+) entry (SOCE) on the plasma membrane. The gene for ORAI1 is located in chromosome 12q24 where a positive linkage signal was observed in our previous affected sib-pair study of KD. A common non-synonymous single nucleotide polymorphism located within exon 2 of ORAI1 (rs3741596) was significantly associated with KD (P = 0.028 in the discovery sample set (729 KD cases and 1,315 controls), P = 0.0056 in the replication sample set (1,813 KD cases vs. 1,097 controls) and P = 0.00041 in a meta-analysis by the Mantel-Haenszel method). Interestingly, frequency of the risk allele of rs3741596 is more than 20 times higher in Japanese compared to Europeans. We also found a rare 6 base-pair in-frame insertion variant associated with KD (rs141919534; 2,544 KD cases vs. 2,414 controls, P = 0.012). These data indicate that ORAI1 gene variations are associated with KD and may suggest the potential importance of the Ca(2+)/NFAT pathway in the pathogenesis of this disorder.


Brain & Development | 2009

An 8-year-old boy with vertebral artery dissection with cerebellar ataxia featuring suspected vertebral artery hypoplasia

Yasuhiko Kawakami; Shinya Koizumi; Kentaro Kuwabara; Juri Fujimura; Junji Shirai; Makoto Watanabe; Satoru Murata; Takehide Imai; Sachiyo Takeda; Ryuji Fukazawa; Masato Takase; Takehisa Fujita; Masatoshi Hida

We report an 8-year-old boy with left vertebral artery dissection featuring cerebellar ataxia in which congenital vertebral artery hypoplasia was suspected as a predisposing factor in the dissection. The patient suddenly suffered from vertigo and vomiting while swimming, and he was brought to our department. The initial brain Computed Tomography (CT) demonstrated no abnormalities, and his symptoms disappeared the next morning. However, one month after onset, brain Magnetic Resonance Imaging (MRI) revealed ischemic changes (infarction) in the left cerebellum. Transfemoral angiography showed complete occlusion at the C2 portion of the left vertebral artery, suggesting dissection and diffuse narrowing of the proximal segment of the occlusion site. Three-dimensional CT angiography also revealed diffuse narrowing of the left vertebral artery from the bifurcation of the subclavian artery. He has since been living daily life without any difficulties. The detailed etiology of cerebral artery dissection remains unknown, but arterial anomalies should be considered as a predisposing factor.


Pediatrics International | 2011

Serum KL-6 and surfactant protein D in children with 2009 pandemic H1N1 influenza infection

Satoko Nishida; Ryuji Fukazawa; Takehide Imai; Sachiyo Takeda; Jun Hayakawa; Hodaka Takeuchi; Kiwako Shimizu; Yasuhiko Kawakami; Masato Takase

Background:u2002 A global pandemic influenza A (H1N1) outbreak occurred in 2009. Rapid progress of respiratory distress is one of the characteristic features of pandemic influenza A (H1N1) infection. The physiologic mechanism causing hypoxia in pandemic influenza A (H1N1) infection, however, has not been elucidated.


The Journal of Pediatrics | 2017

Infliximab for the Treatment of Refractory Kawasaki Disease: A Nationwide Survey in Japan

Hiroshi Masuda; Tohru Kobayashi; Akira Hachiya; Yasutaka Nakashima; Hiroyuki Shimizu; Tomo Nozawa; Yoshihito Ogihara; Shuichi Ito; Shinichi Takatsuki; Nobuyuki Katsumata; Yasuo Suzuki; Satoshi Takenaka; Keiichi Hirono; Tomio Kobayashi; Hiroshi Suzuki; Eisuke Suganuma; Kei Takahashi; Tsutomu Saji; Satoshi Matsuzaki; Shoko Yamazaki; Kazuyuki Ikeda; Takuma Hara; Taichi Kanetaka; Toshitaka Kizawa; Masako Kikuchi; Ryoki Hara; Kentaro Fujii; Mayu Takahashi; Kaori Sonoda; Tomokuni Yoshihashi

Objective To assess the safety and efficacy of infliximab (IFX) for the treatment of patients with Kawasaki disease (KD). Study design This was a nationwide survey of 274 Japanese institutions exploring how IFX was used to treat patients with KD. The patients sex, age, treatment course, pre‐ and post‐IFX therapy blood test results, coronary artery lesions (CALs), and adverse events (AEs) were evaluated. Results We analyzed 434 patients with KD who received IFX between March 2005 and November 2014. The median age at onset was 33 months (range 1–138), and 66 patients (15.2%) were under 1 year old. In all cases, IFX was administered as additional treatment. The median days of illness at the initiation of IFX was 9 days. In 275 patients (63.4%), IFX was administered as third‐line treatment, and in 106 patients (24.4%), IFX was administered as fourth‐line treatment. Single dose IFX 5 mg/kg was administered to 412 patients (94.9%). After IFX, 363 patients (83.6%) became afebrile within 2 days, and the white blood cell count, percentage of neutrophils, and serum C‐reactive protein levels significantly decreased (P < .001), although 119 patients (27.4%) received additional treatment. Before IFX, 132 patients (30.4%) had already developed CALs. In patients without CALs before IFX, 31 patients (10.3%) newly developed CAL after IFX, whereas 32 patients (24.2%) with CAL before IFX showed increased CAL severity. Eighty AEs were observed in 69 patients (15.9%); however, serious AEs were few and reversible. Conclusions IFX might be an effective and tolerable treatment for refractory KD.


JAMA Pediatrics | 2018

Association of Severity of Coronary Artery Aneurysms in Patients With Kawasaki Disease and Risk of Later Coronary Events

Masaru Miura; Tohru Kobayashi; Tetsuji Kaneko; Mamoru Ayusawa; Ryuji Fukazawa; Naoya Fukushima; Shigeto Fuse; Kenji Hamaoka; Keiichi Hirono; Taichi Kato; Yoshihide Mitani; Seiichi Sato; Shinya Shimoyama; Junko Shiono; Kenji Suda; Hiroshi Suzuki; Jun Maeda; Kenji Waki; Hitoshi Kato; Tsutomu Saji; Hiroyuki Yamagishi; Aya Ozeki; Masako Tomotsune; Makiko Yoshida; Yohei Akazawa; Kentaro Aso; Shouzaburoh Doi; Yoshi Fukasawa; Kenji Furuno; Yasunobu Hayabuchi

Importance Few studies with sufficient statistical power have shown the association of the z score of the coronary arterial internal diameter with coronary events (CE) in patients with Kawasaki disease (KD) with coronary artery aneurysms (CAA). Objective To clarify the association of the z score with time-dependent CE occurrence in patients with KD with CAA. Design, Setting, and Participants This multicenter, collaborative retrospective cohort study of 44 participating institutions included 1006 patients with KD younger than 19 years who received a coronary angiography between 1992 and 2011. Main Outcomes and Measures The time-dependent occurrence of CE, including thrombosis, stenosis, obstruction, acute ischemic events, and coronary interventions, was analyzed for small (z score, <5), medium (z score, ≥5 to <10; actual internal diameter, <8 mm), and large (z score, ≥10 or ≥8 mm) CAA by the Kaplan-Meier method. The Cox proportional hazard regression model was used to identify risk factors for CE after adjusting for age, sex, size, morphology, number of CAA, resistance to initial intravenous immunoglobulin (IVIG) therapy, and antithrombotic medications. Results Of 1006 patients, 714 (71%) were male, 341 (34%) received a diagnosis before age 1 year, 501 (50%) received a diagnosis between age 1 and 5 years, and 157 (16%) received a diagnosis at age 5 years or older. The 10-year event-free survival rate for CE was 100%, 94%, and 52% in men (Pu2009<u2009.001) and 100%, 100%, and 75% in women (Pu2009<u2009.001) for small, medium, and large CAA, respectively. The CE-free rate was 100%, 96%, and 79% in patients who were not resistant to IVIG therapy (Pu2009<u2009.001) and 100%, 96%, and 51% in patients who were resistant to IVIG therapy (Pu2009<u2009.001), respectively. Cox regression analysis revealed that large CAA (hazard ratio, 8.9; 95% CI, 5.1–15.4), male sex (hazard ratio, 2.8; 95% CI, 1.7–4.8), and resistance to IVIG therapy (hazard ratio, 2.2; 95% CI, 1.4–3.6) were significantly associated with CE. Conclusions and Relevance Classification using the internal diameter z score is useful for assessing the severity of CAA in relation to the time-dependent occurrence of CE and associated factors in patients with KD. Careful management of CE is necessary for all patients with KD with CAA, especially men and IVIG-resistant patients with a large CAA.

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