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Featured researches published by Ryoichi Kyuragi.


Molecular Therapy | 2013

DVC1-0101 to Treat Peripheral Arterial Disease: A Phase I/IIa Open-label Dose-escalation Clinical Trial

Yoshikazu Yonemitsu; Takuya Matsumoto; Hiroyuki Itoh; Jin Okazaki; Makiko Uchiyama; Kumi Yoshida; Mitsuho Onimaru; Toshihiro Onohara; Hiroyuki Inoguchi; Ryoichi Kyuragi; Mototsugu Shimokawa; Hiroshi Ban; Michiko Tanaka; Makoto Inoue; Tsugumine Shu; Mamoru Hasegawa; Yoichi Nakanishi; Yoshihiko Maehara

We here report the results of a Phase I/IIa open-label four dose-escalation clinical study assessing the safety, tolerability, and possible therapeutic efficacy of a single intramuscular administration of DVC1-0101, a new gene transfer vector based on a nontransmissible recombinant Sendai virus (rSeV) expressing the human fibroblast growth factor-2 (FGF-2) gene (rSeV/dF-hFGF2), in patients with peripheral arterial disease (PAD). Gene transfer was done in 12 limbs of 12 patients with rest pain, and three of them had ischemic ulcer(s). No cardiovascular or other serious adverse events (SAEs) caused by gene transfer were detected in the patients over a 6-month follow-up. No infectious viral particles, as assessed by hemagglutination activity, were detected in any patient during the study. No representative elevation of proinflammatory cytokines or plasma FGF-2 was seen. Significant and continuous improvements in Rutherford category, absolute claudication distance (ACD), and rest pain were observed (P < 0.05 to 0.01). To the best of our knowledge, this is the first clinical trial of the use of a gene transfer vector based on rSeV. The single intramuscular administration of DVC1-0101 to PAD patients was safe and well tolerated, and resulted in significant improvements of limb function. Larger pivotal studies are warranted as a next step.


Journal of Surgical Research | 2011

Reduced proliferation of aged human vascular smooth muscle cells--role of oxygen-derived free radicals and BubR1 expression.

Atsushi Guntani; Takuya Matsumoto; Ryoichi Kyuragi; Kazuomi Iwasa; Toshihiro Onohara; Hiroyuki Itoh; Zvonimir S. Katusic; Yoshihiko Maehara

BACKGROUND Aging is a risk factor for atherosclerosis. Recent studies suggest cell cycle events as well as reactive oxygen species (ROS) contribute to vascular cell dysfunction associated with aging. Mice expressing low levels of the spindle assembly checkpoint protein BubR1 develop aging-associated vascular changes at a young age, including decreased smooth muscle cells and increased reactive oxygen species (ROS) production. This study was designed to determine the effect of aging and production of oxygen-derived free radicals on expression of BubR1. MATERIALS AND METHODS To assess cell proliferation capacity, human aortic smooth muscle cells (hAoSMC) derived from a young group (17-30 y) or an aged group (57-62 y) were cultured, and cell numbers were directly counted in using a Neubauer chamber. RT-PCR assay was used to evaluate BubR1 expression in cultured hAoSMC stimulated with Angiotensin II or H(2)O(2). RESULTS No significant difference in BubR1 expression or hAoSMC proliferative ability was demonstrated at passage 5, but both were significantly decreased at passage 8 in the aged hAoSMC. Angiotensin II and H(2)O(2) up-regulated BubR1 expression in young hAoSMC, and the up-regulation was abrogated by a p38 MAPK inhibitor or an inhibitor of the NADH/NADPH oxidase. siRNA against BubR1 reduced proliferative activity and increased ROS production in hAoSMC. CONCLUSIONS These findings demonstrate BubR1 mRNA expression decreases along with proliferation in aged hAoSMC. Aging-related loss of BubR1 and subsequent impairment of reactivity to ROS may explain reduced proliferative capacity of aged smooth muscle cells.


Surgery Today | 2015

Midterm outcomes of endovascular repair for abdominal aortic aneurysms with the on-label use compared with the off-label use of an endoprosthesis

Takuya Matsumoto; Shinichi Tanaka; Jun Okadome; Ryoichi Kyuragi; Ryota Fukunaga; Eisuke Kawakubo; Hiroyuki Itoh; Jin Okazaki; Ken Shirabe; Atsushi Fukuda; Yoshihiko Maehara

PurposeEndovascular repair of an abdominal aortic aneurysm (EVAR) is sometimes not performed in accordance with the instructions for use (IFU) of the endoprosthesis (“off-label use”). We investigated whether the off-label use of the endograft affected the outcomes of EVAR.MethodsDemographic, anatomical, intraoperative and follow-up data on 100 patients in whom the endograft was used on-label in EVAR were compared retrospectively with the corresponding data of 50 patients with off-label endograft use.ResultsThe endograft IFU were most often not followed in patients with challenging aortic neck anatomy or iliac access or fixation, steep neck angulation or bilateral hypogastric artery embolization. Compared with patients in whom the device was used on-label, patients with off-label use had significantly higher rates of intraoperative type I or III endoleaks and proximal aortic cuff placement or other adjunctive procedures. However, there were no midterm differences between the two groups in the rates of type 1b or II endoleaks, sac enlargement, device–limb occlusion or patient survival.ConclusionsMost midterm outcomes of EVAR in which the endografts were used off-label were similar to those associated with on-label use of the devices. Off-label use of EVAR endoprostheses is feasible, but requires the use of special techniques in patients with challenging anatomical features.


Annals of Vascular Diseases | 2011

Fibromuscular Dysplasia of the Lower Extremities

Jin Okazaki; Atsushi Guntani; Kenichi Homma; Ryoichi Kyuragi; Eisuke Kawakubo; Yoshihiko Maehara

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, non-inflammatory vascular disease that mainly affects the renal and internal carotid arteries. Involvement of other sites, including arteries of the extremities, is uncommon, and only a few histologically confirmed cases have been reported. FMD of the arteries of the extremities can result in ischemia requiring surgical or endovascular reconstruction. In the present report, two cases of FMD are described: one case of femoropopliteal artery occlusive disease, and one case of nonsymptomatic progression of external iliac artery dissection, both with histological confirmation of FMD. Clinical presentation, treatment, outcome and histological findings of previously reported cases are reviewed. FMD should be considered as a cause of occlusion, stenosis, dissection or aneurysm of the peripheral arteries: although rare, it can lead to limb-threatening ischemia or life-threatening aneurysm rupture.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2015

BubR1 Insufficiency Inhibits Neointimal Hyperplasia Through Impaired Vascular Smooth Muscle Cell Proliferation in Mice

Ryoichi Kyuragi; Takuya Matsumoto; Yui Harada; Satoru Saito; Mitsuho Onimaru; Yoshimichi Nakatsu; Teruhisa Tsuzuki; Masatoshi Nomura; Yoshikazu Yonemitsu; Yoshihiko Maehara

Objective—BubR1, a cell cycle–related protein, is an essential component of the spindle checkpoint that regulates cell division. Mice with BubR1 expression reduced to 10% of the normal level display a phenotype characterized by progeria; however, the involvement of BubR1 in vascular diseases is still unknown. We generated mice in which BubR1 expression was reduced to 20% (BubR1L/L mice) of that in wild-type mice (BubR1+/+) to investigate the effects of BubR1 on arterial intimal hyperplasia. Approach and Results—Ten-week-old male BubR1L/L and age-matched wild-type littermates (BubR1+/+) were used in this study. The left common carotid artery was ligated, and histopathologic examinations were conducted 4 weeks later. Bone marrow transplantation was also performed. Vascular smooth muscle cells (VSMCs) were isolated from the thoracic aorta to examine cell proliferation, migration, and cell cycle progression. Severe neointimal hyperplasia was observed after artery ligation in BubR1+/+ mice, whereas BubR1L/L mice displayed nearly complete inhibition of neointimal hyperplasia. Bone marrow transplantation from all donors did not affect the reconstitution of 3 hematopoietic lineages, and neointimal hyperplasia was still suppressed after bone marrow transplantation from BubR1+/+ mice to BubR1L/L mice. VSMC proliferation was impaired in BubR1L/L mice because of delayed entry into the S phase. VSMC migration was unaffected in these BubR1L/L mice. p38 mitogen–activated protein kinase–inhibited VSMCs showed low expression of BubR1, and BubR1-inhibited VSMCs showed low expression of p38. Conclusions—BubR1 may represent a new target molecule for treating pathological states of vascular remodeling, such as restenosis after angioplasty.


Human Gene Therapy Methods | 2013

Ex Vivo Generation of Highly Purified and Activated Natural Killer Cells from Human Peripheral Blood

Satoru Saito; Yui Harada; Yosuke Morodomi; Mitsuho Onimaru; Kumi Yoshida; Ryoichi Kyuragi; Hisahiro Matsubara; Yoshikazu Yonemitsu

Adoptive immunotherapy using natural killer (NK) cells has been a promising treatment for intractable malignancies; however, there remain a number of difficulties with respect to the shortage and limited anticancer potency of the effector cells. We here established a simple feeder-free method to generate purified (>90%) and highly activated NK cells from human peripheral blood-derived mononuclear cells (PBMCs). Among the several parameters, we found that CD3 depletion, high-dose interleukin (IL)-2, and use of a specific culture medium were sufficient to obtain highly purified, expanded (∼200-fold) and activated CD3(-)/CD56(+) NK cells from PBMCs, which we designated zenithal-NK (Z-NK) cells. Almost all Z-NK cells expressed the lymphocyte-activated marker CD69 and showed dramatically high expression of activation receptors (i.e., NKG2D), interferon-γ, perforin, and granzyme B. Importantly, only 2 hours of reaction at an effector/target ratio of 1:1 was sufficient to kill almost all K562 cells, and the antitumor activity was also replicated in tumor-bearing mice in vivo. Cytolysis was specific for various tumor cells, but not for normal cells, irrespective of MHC class I expression. These findings strongly indicate that Z-NK cells are purified, expanded, and near-fully activated human NK cells and warrant further investigation in a clinical setting.


Annals of Vascular Diseases | 2012

Clinical Results of Endovascular Abdominal Aortic Aneurysm Repair in Patients with Renal Insufficiency without Hemodialysis.

Atsushi Guntani; Jyun Okadome; Eisuke Kawakubo; Ryoichi Kyuragi; Kazuomi Iwasa; Ryota Fukunaga; Sosei Kuma; Takuya Matsumoto; Jin Okazaki; Yoshihiko Maehara

OBJECTIVE Chronic renal insufficiency may be a relative contraindication to endovascular aneurysm repair (EVAR) for the use of contrast enhanced mediums. It is thought that more contrast enhanced media are needed in patients who are not anatomically suitable for EVAR, because of procedural difficulties. We reviewed a 2 year EVAR experience at our institution to determine whether the procedure and use of contrast enhanced mediums has any deleterious effect on renal function in patients with pre-existing chronic renal insufficiency. MATERIALS AND METHODS EVAR was performed in 46 patients with pre-existing chronic renal insufficiency without hemodialysis. Patients were retrospectively assigned to two groups on the basis of their preoperative creatinine clearance levels. Furthermore, patients were assigned to two other groups on the basis of anatomical suitability for EVAR. The absolute change in the serum creatinine (Cr) level was reviewed in the each renal insufficiency group between the preoperative and post-operative time periods. RESULTS No increase in the serum Cr level was noted, and no patient required temporary or permanent hemodialysis, in any of the groups. CONCLUSIONS EVAR with contrast agents can be accomplished in patients with chronic renal insufficiency without hemodialysis; therefore,elevated Cr levels maynot be a contraindication in EVAR.


Surgery Today | 2011

Successful treatment of a visceral artery aneurysm with a celiacomesenteric trunk: report of a case.

Atsushi Guntani; Terutoshi Yamaoka; Ryoichi Kyuragi; Kenichi Honma; Kazuomi Iwasa; Takuya Matsumoto; Takashi Nishizaki; Yoshihiko Maehara

A celiacomesenteric trunk is an anomaly in which the celiac and superior mesenteric arteries have a common origin from the aorta. This structure accounts for less than 1% of all visceral artery anomalies, and is estimated to have an incidence of 0.25%. Aneurysms involving a celiacomesenteric trunk are exceptionally rare. We herein report our treatment modality for an 82-year-old man with a visceral artery aneurysm involving a celiacomesenteric trunk. The aneurysm was resected, and the superior mesenteric, splenic, and common hepatic arteries were successfully reconstructed.


Annals of Vascular Diseases | 2013

Evaluation of the Paramalleolar Bypass for Critical Limb Ischemia Patients on Hemodialysis with Diabetes Mellitus and Chronic Renal Failure

Atsushi Guntani; Terutoshi Yamaoka; Jun Okadome; Eisuke Kawakubo; Ryoichi Kyuragi; Kenichi Homma; Kazuomi Iwasa; Takuya Matsumoto; Jin Okazaki; Yoshihiko Maehara

OBJECTIVE To assess the influence of diabetes mellitus (DM) and end-stage renal failure on hemodialysis (HD) on the healing time of tissue lesions and blood flow to the foot following a paramalleolar bypass in patients with critical limb ischemia (CLI). METHODS Consecutive patients with CLI and tissue loss (24 limbs) were followed up retrospectively after paramalleolar bypass, and the healing time of tissue lesions, graft patency, limb salvage and survival rates were analyzed. The blood flow to the foot was assessed by skin perfusion pressure (SPP) pre- and postoperatively. The delta SPP was calculated as the difference between the SPP before and after bypass. The patients were divided into 3 groups: diabetic (DM, n = 9); diabetic and end-stage renal failure on hemodialysis (HD, n = 10); or neither (n = 5). RESULTS A total of 15 dorsal and 9 plantar artery bypasses were performed. The median follow-up was 7.3 months (range, 1-18 months). No patients required major amputations, and all tissue lesions healed. The mean duration to complete tissue healing of the DM, HD and neither groups was 2.2, 2.5 and 1.2 months, respectively, was and these were not statistically significant. A significant improvement in the delta SPP after paramalleolar bypass was observed in the neither group compared with both the DM and HD groups. CONCLUSION Blood flow to the foot was not sufficiently improved in CLI patients with DM and HD, despite paramalleolar bypass. This may be the cause of the prolonged tissue healing duration of CLI patients with DM and HD. (English Translation of Jpn J Vasc Surg 2012; 21: 91-95).


Hukuoka acta medica | 2015

Long-Term Results of a Hybrid Revascularization Procedure for Peripheral Arterial Disease.

Jun Okadome; Takuya Matsumoto; Yukihiko Aoyagi; Daisuke Matsuda; Shinichi Tanaka; Eisuke Kawakubo; Ryoichi Kyuragi; Kouichi Morisaki; Kenichi Homma; Kazuomi Iwasa; Takahiro Ohmine; Atsushi Guntani; Ryota Fukunaga; Yoshihiko Maehara

OBJECTIVE To evaluate the efficacy of hybrid procedure for peripheral arterial disease (PAD), we compared the cases treated using the hybrid procedure with those treated using open revascularization (bypass alone) in our facilities. MATERIALS AND METHODS We retrospectively reviewed 204 patients who underwent revascularization for PAD between 2007 and 2013. We divided the patients into two groups based on the type of procedure. Group 1 included patients who underwent the hybrid procedure, that is, doing endovascular therapy (EVT) either femoral or iliac resion and added the bypass procedure (infragenicular vein bypass) to the below knee artery, and group 2 included patients who underwent only bypass procedure (used autovein), that is, central anastomotic region was femoral artery region and peripheral anastomotic region was below knee artery. We evaluated various factors between the two groups, including the primary patency rate, secondary patency rate, amputation-free survival rate, and determined the efficacy of the hybrid procedure for PAD. RESULTS In the patients characteristics, there was significant difference between the two groups in the cases with cerebrovascular disease, only (p = 0.03). There were no significant differences in the primary or secondary patency rates, and the amputation-free survival rate. CONCLUSIONS Primary patency rate, secondary patency rate, and amputation-free survival rate of the hybrid procedure were comparable to those of bypass (alone) procedure. The hybrid procedure is therefore an acceptable strategy for patients with PAD.

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