2024/02/01 更新

写真a

ミヤギ ヤスオ
宮城 泰雄
Miyagi Yasuo
所属
付属病院 医療安全管理部 准教授
職名
准教授
外部リンク

研究キーワード

  • 再生医療

論文

  • Shunt and pace: a novel experimental model of atrial fibrillation with a volume-loaded left atrium.

    Hiroya Ohmori, Shun-Ichiro Sakamoto, Yasuo Miyagi, Yosuke Ishii, Takashi Nitta

    General thoracic and cardiovascular surgery   71 ( 5 )   272 - 279   2023年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Atrial fibrillation (AF) is frequently seen in patients with a volume-loaded left atrium (LA) such as mitral valve regurgitation (MR). Previous animal models have incomplete relevance to human AF associated with MR. METHODS: A novel experimental model with a combination of volume loading of LA by creating a shunt from the subclavian artery to pulmonary artery and electrical remodeling induced by continuous rapid LA pacing was designed and the electrophysiological effects were examined in 10 canines. Five weeks after the shunt surgery, the entire atrial epicardium was mapped during sustained AF with form-fitted electrode patches with 246 bipolar electrodes and a three-dimensional dynamic mapping system to characterize the induced AF. RESULTS: Three animals died of severe heart failure and pacing failure occurred in one. Remaining six animals were subjected to the analysis. The LA diameter increased progressively after the shunt surgery. Sustained AF was induced after 3 weeks of continuous rapid LA pacing in all animals. The activation maps revealed repetitive focal activations arising from the pulmonary veins, right or left atrial regions, and reentrant activations in the RA, which patterns of atrial activations are the same as those seen in human AF. CONCLUSION: The animal model with a combination of LA volume load and electrical remodeling was relevant to human AF associated with LA volume load. Studies using the present model may provide further knowledges of AF and may be useful in examining the effects of pharmacological and non-pharmacological therapies.

    DOI: 10.1007/s11748-022-01866-8

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  • Surgical Management of Cardiac Implantable Electronic Device Complications in Patients Unsuitable for Transvenous Lead Extraction.

    Yasuo Miyagi, Hiroya Oomori, Motohiro Maeda, Tomohiro Murata, Keisuke Ota, Yusuke Motoji, Ryosuke Amitani, Hitomi Ueda, Motoko Morishima, Takayoshi Matsuyama, Jiro Kurita, Yuji Maruyama, Takashi Sasaki, Shun-Ichiro Sakamoto, Yosuke Ishii

    Circulation journal : official journal of the Japanese Circulation Society   87 ( 1 )   103 - 110   2022年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Although surgical approaches for infected or failing cardiac implantable electronic device (CIED) leads are more invasive than transvenous approaches, they are still required for patients considered unsuitable for transvenous procedures. In this study, surgical management with transvenous equipment for CIED complications was examined in patients unsuitable for transvenous lead extraction.Methods and Results: We retrospectively examined 152 consecutive patients who underwent CIED extraction between April 2009 and December 2021 at the Department of Cardiovascular Surgery, Nippon Medical School. Nine patients (5.9%; mean [±SD] age 61.7±16.7 years) who underwent open heart surgery were identified as unsuitable for the isolated transvenous approach. CIED types included 5 pacemakers and 4 implantable cardioverter-defibrillators; the mean [±SD] lead age was 19.5±7.0 years. Indications for surgical management according to Heart Rhythm Society guidelines included failed prior to transvenous CIED extraction (n=6), intracardiac vegetation (n=2), and severe lead adhesion (n=1). Transvenous CIED extraction tools were used in all patients during or before surgery. Additional surgical procedures with CIED extraction included epicardial lead implantation (n=4) and tricuspid valve repair (n=3). All patients were discharged; during the follow-up period (mean 5.7±3.7 years), only 1 patient died (non-cardiac cause). CONCLUSIONS: Surgical procedures and transvenous extraction tools were combined in the removal strategy for efficacious surgical management of CIED leads. Intensive surgical procedures were safely performed in patients unsuitable for transvenous extraction.

    DOI: 10.1253/circj.CJ-22-0456

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  • Statins Show Anti-Atherosclerotic Effects by Improving Endothelial Cell Function in a Kawasaki Disease-like Vasculitis Mouse Model. 国際誌

    Yusuke Motoji, Ryuji Fukazawa, Ryosuke Matsui, Yoshinori Abe, Ikuno Uehara, Makoto Watanabe, Yoshiaki Hashimoto, Yasuo Miyagi, Noriko Nagi-Miura, Nobuyuki Tanaka, Yosuke Ishii

    International journal of molecular sciences   23 ( 24 )   2022年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Kawasaki disease (KD) is an acute inflammatory syndrome of unknown etiology that is complicated by cardiovascular sequelae. Chronic inflammation (vasculitis) due to KD might cause vascular cellular senescence and vascular endothelial cell damage, and is a potential cause of atherosclerosis in young adults. This study examined the effect of KD and HMG-CoA inhibitors (statins) on vascular cellular senescence and vascular endothelial cells. Candida albicans water-soluble fraction (CAWS) was administered intraperitoneally to 5-week-old male apolipoprotein E-deficient (ApoE-) mice to induce KD-like vasculitis. The mice were then divided into three groups: control, CAWS, and CAWS+statin groups. Ten weeks after injection, the mice were sacrificed and whole aortic tissue specimens were collected. Endothelial nitric oxide synthase (eNOS) expression in the ascending aortic intima epithelium was evaluated using immunostaining. In addition, eNOS expression and levels of cellular senescence markers were measured in RNA and proteins extracted from whole aortic tissue. KD-like vasculitis impaired vascular endothelial cells that produce eNOS, which maintains vascular homeostasis, and promoted macrophage infiltration into the tissue. Statins also restored vascular endothelial cell function by promoting eNOS expression. Statins may be used to prevent secondary cardiovascular events during the chronic phase of KD.

    DOI: 10.3390/ijms232416108

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  • Kawasaki Disease-like Vasculitis Facilitates Atherosclerosis, and Statin Shows a Significant Antiatherosclerosis and Anti-Inflammatory Effect in a Kawasaki Disease Model Mouse. 国際誌

    Yusuke Motoji, Ryuji Fukazawa, Ryosuke Matsui, Noriko Nagi-Miura, Yasuo Miyagi, Yasuhiko Itoh, Yosuke Ishii

    Biomedicines   10 ( 8 )   2022年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Kawasaki disease (KD) is an acute form of systemic vasculitis that may promote atherosclerosis in adulthood. This study examined the relationships between KD, atherosclerosis, and the long-term effects of HMG-CoA inhibitors (statins). Candida albicans water-soluble fraction (CAWS) was injected intraperitoneally into 5-week-old male apolipoprotein-E-deficient (Apo E-/-) mice to create KD-like vasculitis. Mice were divided into 4 groups: the control, CAWS, CAWS+statin, and late-statin groups. They were sacrificed at 6 or 10 weeks after injection. Statin was started after CAWS injection in all groups except the late-statin group, which was administered statin internally 6 weeks after injection. Lipid plaque lesions on the aorta were evaluated with Oil Red O. The aortic root and abdominal aorta were evaluated with hematoxylin and eosin staining and immunostaining. CAWS vasculitis significantly enhanced aortic atherosclerosis and inflammatory cell invasion into the aortic root and abdominal aorta. Statins significantly inhibited atherosclerosis and inflammatory cell invasion, including macrophages. CAWS vasculitis, a KD-like vasculitis, promoted atherosclerosis in Apo E-/- mice. The long-term oral administration of statin significantly suppressed not only atherosclerosis but also inflammatory cell infiltration. Therefore, statin treatment may be used for the secondary prevention of cardiovascular events during the chronic phase of KD.

    DOI: 10.3390/biomedicines10081794

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  • Correction to: Serial change in perfusion-metabolism mismatch after coronary artery bypass grafting.

    Motoko Morishima, Tomonari Kiriyama, Yasuo Miyagi, Toshiaki Otsuka, Yoshimitsu Fukushima, Shin-Ichiro Kumita, Yosuke Ishii

    Annals of nuclear medicine   36 ( 3 )   255 - 255   2022年3月

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  • Serial change in perfusion-metabolism mismatch after coronary artery bypass grafting.

    Motoko Morishima, Tomonari Kiriyama, Yasuo Miyagi, Toshiaki Otsuka, Yoshimitsu Fukushima, Shin-Ichiro Kumita, Yosuke Ishii

    Annals of nuclear medicine   36 ( 3 )   244 - 254   2022年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    OBJECTIVE: Myocardial ischemia is known to suppress fatty acid metabolism and favor glucose metabolism. However, changes in myocardial metabolism after coronary revascularization are not fully elucidated. METHODS: Thirty-eight patients with coronary artery disease were retrospectively enrolled. These patients had undergone stress perfusion single photon emission computed tomography (SPECT) and 123I-BMIPP SPECT in both the short-term (6.4 ± 4.7 months) and mid-term (29.9 ± 7.2 months) after isolated coronary artery bypass grafting. Tracer uptake was graded using a 17-segment, 5-point scoring model. Serial changes in SRS (summed rest score), SDS (summed difference score), the BMIPP score (total defect score of BMIPP), and the mismatch score (BMIPP score-SRS) were evaluated. In addition, persistent perfusion-metabolism mismatch (PM) was defined as mismatch score minus SDS of 3 or more during the mid-term postoperative period. The clinical parameters associated with PM were examined. RESULTS: From short- to mid-term postoperative period, the extent of infarcted myocardium (SRS) did not change significantly (7.8 ± 8.0 to 7.1 ± 7.0, P = 0.117). The extent of ischemic myocardium (SDS), the BMIPP score and the mismatch score, which reflects perfusion-metabolism mismatch, were significantly improved (2.0 ± 2.8 to 0.7 ± 1.0, P = 0.010; 12.2 ± 9.0 to 9.5 ± 7.9, P < 0.001; 4.4 ± 3.7 to 2.5 ± 2.6, P < 0.001; respectively). Remarkably, perfusion-metabolism mismatch persisted in 13 patients (34%) even in the mid-term postoperative period. eGFR and SYNTAX score were independent predictors of persistent perfusion-metabolic mismatch in multivariable analysis (OR = 0.951, 95% CI 0.898-0.985, P = 0.010 and OR = 1.126, 95% CI 1.011-1.254, P = 0.031, respectively). The mismatch score both in the short- and mid-term significantly correlated with SYNTAX score (r = 0.400 and r = 0.472, respectively). CONCLUSIONS: Fatty acid metabolism disturbance improved from short- to mid-term postoperative period in patients with successful reperfusion by coronary artery bypass grafting. However, in patients with severe atherosclerosis, impaired fatty acid metabolism was sustained until the mid-term postoperative period, even though ischemia had resolved.

    DOI: 10.1007/s12149-021-01696-3

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  • Outcomes of abdominal aortic aneurysm repairs: Endovascular vs open surgical repairs. 国際誌

    Boonying Siribumrungwong, Jiro Kurita, Tatsuo Ueda, Daisuke Yasui, Ken-Ichiro Takahashi, Takashi Sasaki, Yasuo Miyagi, Shun-Ichiro Sakamoto, Yosuke Ishii, Tetsuro Morota, Takashi Nitta

    Asian journal of surgery   45 ( 1 )   346 - 352   2022年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Operative mortality after endovascular aneurysm repair (EVAR) has been reported as lower than open surgical repair (OSR) for abdominal aortic aneurysm (AAA) in randomized controlled trials. However, many cohort studies have demonstrated similar mortality rates for both procedures. We compared operative mortality between EVAR and OSR, at our institution. METHODS: All AAA operations from 2012 to 2017 were reviewed, and baseline characteristics were collected. Outcomes included 30-day mortality, operative data, complications, length of hospital stay (LOS), costs, re-intervention, and survival rates were compared. A multivariable analysis with unbalanced characteristics was performed. RESULTS: We had a total of 162 patients, 100 having OSR and 62 for EVAR. The EVAR group was older, with higher ASA classification. Thirty-day mortality rate did not significantly differ (0/100 for OSR and 2/62 (3%) for EVAR; p = 0.145), while the EVAR group had less blood loss, shorter operative times, and LOS, but higher re-intervention rates (adjusted hazard ratio 6.4 (95%CI: 1.4, 26.8)). Survival rates did not significantly differ between the groups. EVAR cost approximately 1-million yen more. CONCLUSIONS: OSR had low 30-day mortality rate in selected low-risk patients whereas EVAR had less blood loss, shorter operative times, LOS and could be done in high-risk patients with low 30-day mortality but with higher re-intervention rate.

    DOI: 10.1016/j.asjsur.2021.06.015

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  • Four-dimensional flow analysis reveals mechanism and impact of turbulent flow in the dissected aorta. 国際誌

    Kenichiro Takahashi, Tetsuro Sekine, Yasuo Miyagi, Sayaka Shirai, Toshiaki Otsuka, Shinichiro Kumita, Yosuke Ishii

    European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery   60 ( 5 )   1064 - 1072   2021年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    OBJECTIVES: This study aimed to explore the flow dynamics factors affecting turbulence formation in the false lumen (FL) of aortic dissection using four-dimensional flow magnetic resonance imaging (4D flow MRI). This study also aimed to uncover risk factors affecting late complications of aortic dissection. METHODS: Thirty-three aortic dissection patients were examined using 4D flow MRI for quantitative flow dynamics (gross flow, velocity and regurgitant fraction) and turbulence visualization (helix and vortex with three-point visual grading) in the FL. The incidence of late complications (rupture or prophylactic intervention) was also obtained prospectively. RESULTS: The helix grade was correlated with FL gross flow (rS = 0.55, P < 0.001) and FL velocity (rS = 0.45, P = 0.008). The vortex grade was also correlated with FL gross flow (rS = 0.70, P < 0.001) and FL velocity (rS = 0.67, P < 0.001). Comparative analysis of patients with complications and stable patients revealed that patients with complications exhibited higher FL gross flow [41.7 (interquartile range, IQR 29.1-59.7) vs 17.7 (IQR 9.0-42.0) ml/s; P = 0.01], higher helix grade [2 (IQR 1.25-2) vs 0 (IQR 0-1); P = 0.001] and higher vortex grade [2 (IQR 1-2) vs 0 (IQR 0-2); P = 0.01]. CONCLUSIONS: Using 4D flow MRI analysis, we showed that turbulence formation depends on flow volume and velocity in the FL. Patients with high-volume turbulent flow in their FL are at higher risk of late complications; therefore, close follow-up and aggressive prophylactic intervention may improve their survival. CLINICAL TRIAL REGISTRATION NUMBER: Nippon Medical School Hospital Institutional Review Board approved this observational study in September 2018 (No. 30-08-986).

    DOI: 10.1093/ejcts/ezab201

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  • Temporal and Microbiological Analysis of Cardiac Implantable Electrical Device Infections - A Retrospective Study.

    Yasuo Miyagi, Shun-Ichiro Sakamoto, Yasuhiro Kawase, Hiroya Oomori, Yoshiyuki Watanabe, Jiro Kurita, Yuji Maruyama, Takashi Sasaki, Yosuke Ishii

    Circulation reports   3 ( 9 )   488 - 496   2021年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Background: Although the causative pathogens in cardiac implantable electronic device (CIED) infections are well known, the relationship between time after implantation and infection patterns has not been sufficiently investigated. This study investigated the microbiology and onset of CIED infections according to infection patterns. Methods and Results: This retrospective study included 97 patients who underwent CIED removal due to device-related infections between April 2009 and December 2018. After device implantation, infections peaked in the first year and declined gradually over 10 years. Most infections (>60%) occurred within 5 years. Staphylococcal infections, the predominant form of CIED infections, occurred throughout the study period. CIED infections were categorized as systemic (SI; n=26) or local (LI; n=71) infections according to clinical presentation, and as CIED pocket-related (PR; n=85) and non-pocket-related (non-PR; n=12) infections according to the pathogenic pathway. The main causative pathogen in SI was Staphylococcus aureus, whereas coagulase-negative staphylococci were mainly related to LI. Both SI and LI peaked in the first year after implantation and then decreased gradually. There was no significant microbiological difference between PR and non-PR infections. PR infections showed the same temporal distribution as the overall cohort. However, non-PR infections exhibited a uniform temporal distribution after the first year. Conclusions: The severity of CIED infections depends on the causative pathogen, whereas their temporal distribution is affected by the microbiological intrusion pathway.

    DOI: 10.1253/circrep.CR-21-0095

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  • The Effect of Continuous Field Block through Intercostal Muscles after Atrial Septal Defect Closure via a Mini-Right Thoracotomy in Pediatric Patients.

    Kenji Suzuki, Takashi Sasaki, Yasuo Miyagi, Keisuke Mori, Hiroaki Kishikawa, Yosuke Ishii, Atsuhiro Sakamoto, Takashi Nitta

    Journal of Nippon Medical School = Nippon Ika Daigaku zasshi   88 ( 4 )   347 - 353   2021年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Postoperative pain management in thoracotomy patients often is difficult. Furthermore, pediatric patients present more challenges because of their inability to effectively communicate their pain intensity. The purpose of this study was to evaluate the use of continuous field block through intercostal muscles as postoperative pain management in pediatric thoracotomy. METHODS: Between 2014 and 2018, 11 patients underwent an ASD closure using a cardiopulmonary bypass via a mini-right thoracotomy through the fourth intercostal space. At the time of chest closure, a single-shot field block via the fourth intercostal muscles was performed with levobupivacaine (0.6 mg/kg). The first five patients were only given the single-shot field block (Single group). The remaining six patients were given levobupivacaine continuously (0.1 mg/kg/hr) through an indwelling catheter until the chest tube removal (Continuous group). The groups' vital signs, total amounts of acetaminophen used, postoperative courses were compared. RESULTS: Although the heart rate did not differ between the groups, the respiratory rate was significantly higher in the Single group versus the Continuous group at 16 and 32 hr post-surgery (35.6 ± 9.7/min vs. 18.5 ± 4.7/min; p=0.007, 43.0 ± 10.4 vs. 25.3 ± 3.1; p=0.042, respectively). The accumulated dosage of acetaminophen given by postoperative day 2 was significantly higher in the Single group versus the Continuous group (55.3 ± 22.1 mg/kg vs. 7.8 ± 17.4 mg/kg; p=0.012). CONCLUSIONS: Continuous field block via intercostal muscles after ASD closure via a mini-right thoracotomy in children was effective to stabilize the vital signs and reduce the analgesic medication use.

    DOI: 10.1272/jnms.JNMS.2021_88-507

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  • Computational fluid dynamics simulations of flow distribution and graft designs in apicoaortic bypass.

    Takashi Sasaki, Hitomi Ueda, Keiichi Itatani, Kenji Suzuki, Jiro Kurita, Shun-Ichiro Sakamoto, Yasuo Miyagi, Yosuke Ishii, Tetsuro Morota, Takashi Nitta

    General thoracic and cardiovascular surgery   69 ( 5 )   811 - 818   2021年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    OBJECTIVE: Apicoaortic bypass has double outlets and its graft design is similar to that of a left ventricular assist device (LVAD). The left ventricular apex to the descending aorta (LV-DsAo) bypass is widely used in apicoaortic bypass. In contrast, the left ventricular apex to the ascending aorta (LV-AsAo) bypass is standard in LVAD surgery. This study aimed to evaluate the graft designs of apicoaortic bypass and their effects on flow distribution and energy loss (EL). METHODS: A simulation study using computational fluid dynamics was performed on the geometry and hemodynamics data obtained from a 30-year-old patient who underwent a LV-DsAo bypass. The ratio of the cardiac output (CO) through the ascending aorta (AsAo) and apicoaortic conduit was set at 50:50, 30:70, and 10:90. Regional blood flow (RBF) and EL were calculated for the different distribution ratios. As an alternative to the LV-DsAo bypass, a virtual LV-AsAo bypass surgery was performed, and each parameter was compared with that of the LV-DsAo bypass. RESULTS: At a distribution ratio of 50:50, the RBF to the head and EL were 16.4% of the total CO and 62.0 mW in the LV-DsAo bypass, and 32.3% and 81.5 mW in the LV-AsAo bypass, respectively. The RBF to the head decreased with the CO through the AsAo in the LV-DsAo bypass, but it was constant in the LV-AsAo bypass. The EL increased inversely with the CO through the AsAo in both graft designs. CONCLUSION: The regional blood flow distribution was different, but the trend of the EL which increased inversely with the CO through the AsAo was similar between the LV-DsAo and LV-AsAo bypasses.

    DOI: 10.1007/s11748-020-01527-8

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  • Transvenous implantable cardioverter-defibrillator implantation in a patient with arrhythmogenic cardiomyopathy and massive right atrial thrombus. 国際誌

    Hiroshi Hayashi, Yu-Ki Iwasaki, Toshiki Seki, Kanako Hagiwara, Yasuo Miyagi, Wataru Shimizu

    HeartRhythm case reports   6 ( 12 )   951 - 954   2020年12月

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  • Novel treatment of vascular injury from delayed hemodialysis catheter migration by transvenous balloon-assisted embolization with n-butyl cyanoacrylate. 国際誌

    Ryutaro Fujitsuna, Fumie Sugihara, Daisuke Yasui, Hidemasa Saito, Tatsuo Ueda, Sayaka Shirai, Taiga Matsumoto, Yasuo Miyagi, Shin-Ichiro Kumita

    Radiology case reports   15 ( 9 )   1450 - 1454   2020年9月

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    記述言語:英語  

    Delayed vascular injury (DVI) with a hemodialysis catheter is a rare but potentially life-threatening complication. However, the appropriate treatment for DVI has not yet been established. A 44-year-old man underwent placement of a hemodialysis catheter via the left internal jugular vein, and the first leukapheresis procedure was performed without complications. However, 3 days after the insertion of the hemodialysis catheter, the patient developed sudden dyspnea. Chest radiographs and contrast-enhanced computed tomography revealed that the catheter tip had migrated and was located outside the left brachiocephalic vein. DVI with catheter migration was diagnosed. To perform safe and reliable hemostasis, we successfully performed transvenous balloon-assisted tract embolization with n-butyl cyanoacrylate and the catheter was removed. To our knowledge, there has been no previous report of the treatment of balloon-assisted tract embolization with n-butyl cyanoacrylate for DVI caused by a hemodialysis catheter. Our treatment approach may be safe and effective for DVI.

    DOI: 10.1016/j.radcr.2020.05.077

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  • Histological properties of oscillating intracardiac masses associated with cardiac implantable electric devices.

    Yasuo Miyagi, Yasuhiro Kawase, Shinobu Kunugi, Hiroya Oomori, Takashi Sasaki, Shun-Ichiro Sakamoto, Yosuke Ishii, Tetsuro Morota, Takashi Nitta, Akira Shimizu

    Journal of arrhythmia   36 ( 3 )   478 - 484   2020年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: There have been a few cases of echogenic cardiac implantable electric device (CIED) lead-associated oscillating intracardiac masses (ICMs) in leads imaged by echocardiography. The histological properties of ICMs could help clarify the etiological diagnosis. Although there is extensive literature on mass size, the histological properties of such masses have not been characterized. The aim of this research was to clarify the histological features of oscillating ICMs in CIED patients. METHODS: Preoperative echocardiography was performed in all candidates for CIED removal. In the patients with ICMs, specimens were obtained by 3 methods: direct tissue collection during open-heart surgery; tissue collection together with the CIED lead during transvenous extraction; and tissue collection by catheter vacuum during transvenous CIED removal. A standard histopathological examination of ICM tissue was performed. RESULTS: A total of 106 patients underwent lead removal in our institute (April 2009-March 2018); 14 patients had an ICM (13.2%), and 7 specimens were obtained in patients with CIED lead-related ICM. Following histological examination, 2 types of ICM were identified: one mainly composed of thickened endocardium (EN type; 3 patients), and the other mainly an aggregate of inflammatory cells as a neutrophil cell (NC type; 4 patients). CONCLUSIONS: Two histological types of intracardiac masses, including a thickened endocardium type and a neutrophil cell type, were identified. These classifications might help make an accurate histological diagnosis of lead-associated intracardiac masses.

    DOI: 10.1002/joa3.12346

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  • Spatiotemporal imaging documented the maturation of the cardiomyocytes from human induced pluripotent stem cells. 国際誌

    Junya Aoyama, Kohei Homma, Nari Tanabe, Sumiko Usui, Yasuo Miyagi, Katsuhisa Matsuura, Makoto Kaneda, Takashi Nitta

    The Journal of thoracic and cardiovascular surgery   159 ( 6 )   2260 - 2271   2020年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    OBJECTIVES: Cardiomyocytes derived from human induced pluripotent stem cells are a promising source of cells for regenerative medicine. However, contractions in such derived cardiomyocytes are often irregular and asynchronous, especially at early stages of differentiation. This study aimed to determine the differentiation stage of initiation of synchronized and regular contractions, using spatiotemporal imaging and physiological and genetic analyses. METHODS: Knock-in human induced pluripotent stem cell lines were established with clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 to analyze cardiac and pacemaker cell maturation. Time-frequency analysis and Ca2+ imaging were performed, and the expression of related proteins and specific cardiac/pacemaker mRNAs in contracting embryoid bodies was analyzed at various differentiation stages. RESULTS: Time-frequency analysis and Ca2+ imaging revealed irregular, asynchronous contractions at the early stage of differentiation with altered electrophysiological properties upon differentiation. Genes associated with electrophysiological properties were upregulated after 70 days of culturing in differentiation media, whereas pacemaker genes were initially upregulated during the early stage and downregulated at the later stage. CONCLUSIONS: A differentiation period >70 days is required for adequate development of cardiac elements including ion channels and gap junctions and for sarcomere maturation.

    DOI: 10.1016/j.jtcvs.2019.06.060

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  • Negative-pressure sternal wound closure with interrupted subcuticular suturing and a subcutaneous drain tube reduces the incidence of poststernotomy wound infection after coronary artery bypass grafting surgery.

    Masahiro Fujii, Ryuzo Bessho, Yasuo Miyagi, Takashi Nitta

    Surgery today   50 ( 5 )   475 - 483   2020年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    PURPOSES: To retrospectively evaluate the effect of negative-pressure sternal wound closure (NPSWC) with a subcutaneous closed drain tube on the sternal surgical site infection (SSI) incidence. METHODS: After propensity score matching of 231 patients undergoing coronary artery bypass grafting (CABG), we compared 104 pairs in the NPSWC and historical control groups. In the molecular analysis, the interleukin-6 (IL-6), basic fibroblast growth factor (b-FGF), and transforming growth factor β1 (TGF-β1) levels in the wound fluid were measured using two different reservoir types at postoperative days 2 and 7. RESULTS: NPSWC significantly reduced the SSI incidence from 10.6 to 2.9%. No mediastinitis occurred in the NPSWC group. A multivariate logistic regression analysis identified female sex (p = 0.0040) and no NPSWC (p = 0.0084) as significant risk factors for sternal SSI development. The Negative-pressure value was 49.4 ± 4.1 and 115.5 ± 15.2 mmHg in the standard-type (SSR) and bulb-type suction reservoirs (BSR), respectively. Given that growth factors were affected by the difference in negative pressure, the IL-6, b-FGF, and TGF-β1 levels were significantly higher in the BSR than in the SSR. CONCLUSIONS: NPSWC using a subcutaneous closed drain tube was effective in preventing sternal SSI after CABG and may accelerate wound healing even when both internal thoracic arteries are harvested. CLINICAL REGISTRATION NUMBER: University Hospital Medical Information Network Clinical Trials Registry, registration number: UMIN000037060.

    DOI: 10.1007/s00595-019-01912-8

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  • 心筋SPECTを用いたCABG術後早期および遠隔期の心筋虚血と脂肪酸代謝の変化の検討

    森嶋 素子, 石井 庸介, 泉二 佑輔, 網谷 亮輔, 上田 仁美, 高橋 賢一朗, 鈴木 憲治, 栗田 二郎, 川瀬 康裕, 佐々木 孝, 宮城 泰雄, 坂本 俊一郎, 師田 哲郎, 桐山 智成, 福嶋 善光, 汲田 伸一郎, 新田 隆

    日本心臓血管外科学会学術総会抄録集   50回   P40 - 4   2020年3月

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    記述言語:日本語   出版者・発行元:(NPO)日本心臓血管外科学会  

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  • Surgical procedure for targeting arrhythmogenic substrates in the treatment of ventricular tachycardia associated with cardiac tumors. 国際誌

    Shun-Ichiro Sakamoto, Atsushi Hiromoto, Hiroshige Murata, Kenji Suzuki, Jiro Kurita, Yasuhiro Kawase, Takashi Sasaki, Yasuo Miyagi, Yosuke Ishii, Tetsuro Morota, Wataru Shimizu, Takashi Nitta

    Heart rhythm   17 ( 2 )   238 - 242   2020年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Complete tumor resection is a standard strategy in the surgical treatment of ventricular tachycardia (VT) associated with cardiac tumors. Recently, an intraoperative electroanatomic mapping system (CARTO) has enabled surgeons to target the localized arrhythmogenic substrate for partial resection and/or cryoablation in nonresectable cardiac tumors. OBJECTIVE: The purpose of this study was to evaluate the surgical procedures and late outcomes of the treatment of VT associated with cardiac tumors. METHODS: We examined six patients (age 1-65 years) who had undergone surgical treatment of VT associated with cardiac tumors between 2010 and 2016. The 4 pathologies of the cardiac tumors were lipoma 2, fibroma 2, hemangioma 1, and lymphoma 1. Intraoperative epicardial mapping using CARTO was performed in 5 patients(80%). Surgical procedures and long-term outcomes were evaluated. RESULTS: Arrhythmogenic substrates with abnormal electrograms, such as fractionated or late potential, were identified locally or circumferentially beside the tumor in every patient. Complete tumor resection with cryoablation was performed in 3 patients. Two patients underwent partial tumor resection with cryoablation. Cryoablation without tumor resection was performed in 1 patient. No mortality and morbidity occurred. Additional catheter ablation was required in 2 patients to treat occurrence of nonclinical VT and induction of clinical VT during hospital stay. Mean follow-up time was 90 ± 52.5 months. There was no recurrence of clinical VT. CONCLUSION: The outcomes of surgical treatment of VT associated with cardiac tumors were excellent. Intraoperative CARTO mapping was beneficial to eliminate the VT substrates associated with nonresectable cardiac tumors.

    DOI: 10.1016/j.hrthm.2019.08.025

    PubMed

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  • Surgical outcomes of modified-maze procedures in adults with atrial septal defect.

    Shun-Ichiro Sakamoto, Atsushi Hiromoto, Yosuke Ishii, Takashi Sasaki, Yasuo Miyagi, Takashi Nitta

    Surgery today   49 ( 2 )   124 - 129   2019年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    PURPOSE: We examined the outcome of modified-maze procedures reflecting a single-center strategy in the treatment of atrial fibrillation (AF) associated with atrial septal defect (ASD) in adults. METHODS: A retrospective chart review was performed for 29 patients who underwent surgical ASD closure and 2 types of maze procedures (full and simplified maze procedures) for AF. The outcome related to the each procedure was examined. A Cox proportional hazards analysis was performed to assess the independent predictors of AF and atrial tachycardia (AT) recurrence. RESULTS: The rates of freedom from AF and AT recurrence at 1 and 4 years were 86.6% and 72.2% in the full maze group and 78.5% and 62.8% in the simplified maze group, respectively (p = 0.70). The only risk factor for recurrence was the age at the time of surgery. A receiver operating characteristic curve analysis gave an optimum cut-off value of 58 years of age for predicting recurrence within 2 years (58.4% for ≥ 58 years versus 5.9% for < 58 years, p = 0.003). CONCLUSIONS: Simplification of the maze procedure was not associated with AF or AT recurrence. The age at the time of surgery might be a clinical predictor of success or failure in adult patients.

    DOI: 10.1007/s00595-018-1709-9

    PubMed

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  • Bovine three-portion pericardial patch for reconstruction of the aorto-mitral curtain in infective endocarditis. 国際誌

    Atsushi Hiromoto, Shun-Ichiro Sakamoto, Yasuo Miyagi, Takashi Nitta

    Surgical case reports   5 ( 1 )   2 - 2   2019年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    BACKGROUND: Surgery for infective endocarditis involving the aorto-mitral curtain (AMC) is challenging and requires extensive incisions and complex reconstruction procedures. However, in patients with preserved aortic annulus, reconstruction of the AMC is possible using a simple technique with limited incisions. CASE PRESENTATION: A handmade bovine three-portion pericardial patch was used to reconstruct the AMC in a patient with severe endocarditis requiring double valve replacement; the technique allowed for steady anchorage of prosthetic valves without additional incisions other than conventional aortotomy and atriotomy. Postoperative echocardiography revealed normal cardiac function and no significant perivalvular leakage. The patient displayed complete recovery and was discharged on postoperative day 33. The patient was symptom-free at his 1-year follow-up and displayed normal laboratory and echocardiographic findings. CONCLUSION: The bovine three-portion pericardial patch is useful for reconstructing the AMC in patients with infective endocarditis accompanied by preserved aortic annulus.

    DOI: 10.1186/s40792-018-0558-5

    PubMed

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  • Enhanced Sternal Healing Through Platelet-Rich Plasma and Biodegradable Gelatin Hydrogel. 国際誌

    Masafumi Shibata, Gen Takagi, Mitsuhiro Kudo, Jiro Kurita, Yoko Kawamoto, Yasuo Miyagi, Mikimoto Kanazashi, Takashi Sakatani, Zenya Naito, Yasuhiko Tabata, Masaaki Miyamoto, Takashi Nitta

    Tissue engineering. Part A   24 ( 17-18 )   1406 - 1412   2018年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Platelet-rich plasma (PRP) contains numerous growth factors and promotes bone fracture healing. The aim of this study was to evaluate the effectiveness of the controlled release of PRP from biodegradable gelatin hydrogel for promoting healing in a rabbit ischemic sternal model. PRP was prepared from the whole blood of a Japanese white rabbit. Sixteen rabbits were randomized into four groups (each n = 4) and all underwent median sternotomy and bilateral internal thoracic artery removal. Before the sternum was closed, the following solutions were applied between the sternum incisions in three of the groups: 30 mg of gelatin hydrogel incorporating 300 μL of phosphate-buffered saline, 300 μL of a solution form of PRP, or 30 mg of gelatin hydrogel incorporating 300 μL of PRP (PRP + Gel). The fourth group acted as a control. Sternal healing was evaluated by histology and microcomputed tomography 7 days after the intervention. The PRP + Gel group showed a significantly higher proportion of fibrosis within the fracture area (an indicator of sternal healing) than the other groups and a significantly higher mean intensity of osteocalcin. These results indicate that the controlled release of PRP from locally applied gelatin hydrogel was markedly effective in enhancing sternal healing in the early postoperative period. This novel therapy could potentially help prevent complications, such as deep sternal wound infection and could result in early postoperative ambulation after median sternotomy.

    DOI: 10.1089/ten.TEA.2017.0505

    PubMed

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  • Risk Factors of Recurrence of Atrial Fibrillation (AF) After AF Surgery in Patients With AF and Mitral Valve Disease. 査読

    Ishii Y, Sakamoto SI, Miyagi Y, Kawase Y, Otsuka T, Nitta T

    30 ( 3 )   271- - 278   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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▼全件表示

MISC

  • 重症呼吸不全に対するECMO導入の上、緊急搬送後に僧帽弁置換術を施行した1例 査読

    前田 基博, 石井 庸介, 井関 陽平, 村田 智洋, 青山 純也, 芝田 匡史, 森嶋 素子, 栗田 二郎, 川瀬 康裕, 佐々木 孝, 坂本 俊一郎, 宮城 泰雄, 師田 哲郎, 市場 晋吾, 新田 隆

    日本胸部外科学会関東甲信越地方会要旨集   ( 172回 )   14 - 14   2016年11月

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    記述言語:日本語   出版者・発行元:日本胸部外科学会-関東甲信越地方会  

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  • リンパ球性下垂体炎を合併した連合弁膜症手術に対する周術期管理の1例

    青山 純也, 石井 庸介, 宮城 泰雄, 坂本 俊一郎, 川瀬 康裕, 白川 真, 森嶋 素子, 鈴木 大悟, 新田 隆, 田原 重志

    日本胸部外科学会関東甲信越地方会要旨集   171st ( 171回 )   27 - 27   2016年6月

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    記述言語:日本語   出版者・発行元:日本胸部外科学会-関東甲信越地方会  

    J-GLOBAL

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  • 急性A型大動脈解離に対する術式の変遷と成績

    芝田 匡史, 師田 哲郎, 藤井 正大, 坂本 俊一郎, 青山 純也, 鈴木 大悟, 森嶋 素子, 栗田 二郎, 白川 真, 川瀬 康裕, 佐々木 孝, 大森 裕也, 宮城 泰雄, 石井 庸介, 新田 隆

    日本血管外科学会雑誌   25 ( Suppl. )   382 - 382   2016年6月

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    記述言語:日本語   出版者・発行元:(NPO)日本血管外科学会  

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  • HVLICを用いたショックリード抵抗値測定による外来ICDチェックの妥当性

    神戸 将, 矢島 俊巳, 栗田 二郎, 藤井 正大, 宮城 泰雄, 石井 庸介, 別所 竜蔵, 落 雅美, 清水 一雄

    Journal of Arrhythmia   23 ( Suppl. )   261 - 261   2007年4月

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    記述言語:日本語   出版者・発行元:(一社)日本不整脈心電学会  

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  • Gap Junctionと不整脈 心筋Gap JunctionにおけるConnexinx43の発現異常と周術期不整脈

    菅野 重人, 新田 隆, 佐々木 孝, 石井 庸介, 大森 裕也, 宮城 泰雄, 丸山 雄二, 藤井 正大, 別所 竜蔵, 矢島 俊巳, 清水 一雄, 別役 徹生

    Journal of Arrhythmia   22 ( Suppl. )   140 - 140   2006年5月

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    記述言語:日本語   出版者・発行元:(一社)日本不整脈心電学会  

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共同研究・競争的資金等の研究課題

  • 多血小板血漿と生分解性徐放化ゲルを用いた新しい心筋再生治療の開発

    研究課題/領域番号:22K08927  2022年4月 - 2027年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    村田 智洋, 宮城 泰雄, 石井 庸介, 栗田 二郎, 網谷 亮輔

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    配分額:2470000円 ( 直接経費:1900000円 、 間接経費:570000円 )

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  • 心外膜植込み型プラットフォームを利用した心臓再生医療の確立

    研究課題/領域番号:22K08946  2022年4月 - 2027年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    宮城 泰雄, 田邉 造, 福原 茂朋

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    配分額:3900000円 ( 直接経費:3000000円 、 間接経費:900000円 )

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  • 小児拡張型心筋症に対する肺動脈絞扼術の有効性の検討

    研究課題/領域番号:20K09136  2020年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    佐々木 孝, 宮城 泰雄, 深澤 隆治

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    配分額:2210000円 ( 直接経費:1700000円 、 間接経費:510000円 )

    1.アドリアマイシンによる心筋障害ラットに対する心臓カテーテル検査:前年度の研究でアドリアマイシンによる薬剤性心筋症モデルを作成の際、若年ラットの生存率が高かったため、4週齢ラット(ヒトの年齢で1.5~2歳相当)を対象とした。15㎎/kgのアドリアマイシンを2週間で6回の分割投与を行った。アドリアマイシン投与の6か月後、29±2週齢で心臓カテーテル検査を施行した(n= 4)。ラットを全身麻酔後、右総頸動脈から逆行性にpressure-volume (PV) conductance catheterを挿入し、先端を左室まで進めて留置した。心拍数288±23 /分、左室収縮期圧97±13mmHg、左室拡張末期圧5±4mmHg、心係数16±6 ml/min/100g、左室駆出率53±7%、1回拍出量255±66μl、左室拡張末期容積543±198μl、収縮末期圧容積関係0.32±0.18、そして拡張末期圧容積関係0.53±0.65であった。文献より同年代のラット正常心のPV conductance catheterによる心機能評価と比較すると、心係数は保たれているものの、左室拡大が著しいことがわかった。収縮性は低下しているが、拡張特性は維持されていた。
    2.アドリアマイシンによる心筋障害モデルの心筋病理評価:上記心臓カテーテル検査後、犠牲死させ、心筋の病理検査を施行した。ヘマトキシリン・エオジン染色で心筋細胞を、マッソン・トリクローム染色で心筋線維化の評価を行った。
    3.肺動脈絞扼術(PAB)モデルの作成:6週齢ラットに胸骨正中切開でアプローチし、主肺動脈に外科クリップをかけPABを施行した。3例に施行し1例が生存した。今後心エコー、心臓カテーテルで心機能を評価した後に犠牲死させ、心筋の病理評価を行う予定である。

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  • 開心術後心房細動を予防する革新的な心房局所に対する抗炎症薬剤徐放化システムの構築

    研究課題/領域番号:18K08745  2018年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    石井 庸介, 丸山 光紀, 工藤 光洋, 宮城 泰雄, 中澤 靖元, 新田 隆

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    配分額:4290000円 ( 直接経費:3300000円 、 間接経費:990000円 )

    今までの臨床研究・基礎研究によって,開心術後心房細動(POAF)の機序が,肺静脈起源の一般的な心房細動とは異なること,心房切開線による局所的な心房の炎症が心房興奮のバラツキを惹起し,POAFの出現に関与していたことが分かった.さらにステロイドの持続大量全身投与がPOAFを予防することが分かったものの,心房局所に対する抗炎症療法がPOAFの予防に有効かどうかはまだ分かっていない。
    本研究では、心房興奮伝導の評価と心房筋における病理学的検討、薬剤徐放化に適したバイオマテリアルの選定を行う予定であった。
    薬剤徐放化に適したバイオマテリアルの選定についてであるが、種々のバイオマテリアルを使用して,心房局所に貼付する臨床応用を目指した抗炎症薬剤徐放化シートの作製を目指して研究を行っているが、徐放化のコントロールに難渋している。
    POAFは臨床において術後10-20日まで出現しているため,術後早期薬剤放出と共に20日間ほど掛けて徐々に薬剤が放出される2段階の薬剤放出を確立する必要があるので難しい。
    心房興奮伝播の評価については、心房切開にて炎症を起こした心房筋に対して,局所の抗炎症療法が興奮伝導のバラツキを抑えることができるか,光学マッピングシステムを使用して調べるシステムを構築している。
    心房における炎症所見を調べ,局所抗炎症療法の効果を病理学的に検証する.ヘマトキシリン・エオジン染色にて好中球の浸潤の程度を調べ,組織中の好中球エラスターゼを測定する試料を作成している、

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  • 心筋細胞細胞外マトリックスグラフト移植による新しい心不全治療の開発

    研究課題/領域番号:17K10742  2017年4月 - 2021年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    宮城 泰雄, 丸山 光紀, 藤井 正大, 時田 祐吉, 太良 修平

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    配分額:4290000円 ( 直接経費:3300000円 、 間接経費:990000円 )

    心筋再生医療の問題点として、移植細胞の生着率と生存率の低値が挙げられる。解決策として、移植細胞外部環境の改善がある。細胞は、細胞外マトリックス(ECM)内で生存しており、組織工学の発達により、多くの人工ECM が開発されてきた。本実験では、心筋細胞を人工ECM上で培養し、心筋細胞ECMグラフトを作成して、傷害心筋表面に移植する。ECMグラフトには、物理学的強度も有し力学的補強を担う。そして、移植された心筋細胞は、傷害心筋で損なわれた心筋興奮伝播を再構築し得る。心筋細胞ECMグラフト移植は、心筋再生医療領域でも細胞移植の有用な基材の応用が考えられ、細胞移植方法の改良に寄与すると予想される。

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  • ダブルポテンシャル法を応用した低侵襲心房細動手術の確立

    研究課題/領域番号:15K10225  2015年4月 - 2018年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    新田 隆, 石井 庸介, 坂本 俊一郎, 宮城 泰雄

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    配分額:4680000円 ( 直接経費:3600000円 、 間接経費:1080000円 )

    心拍動下心外膜アブレーションにおける高周波アブレーションデバイスと凍結凝固アブレーションデバイスの比較により以下のことが明らかとなった。①凍結凝固では完全な全層性壊死巣を作製するにはより時間がかかる。②凍結凝固は弁輪部や冠静脈洞など凍結範囲が比較的狭い部位に適している。③心房自由壁における比較的長い線状凍結においては、全長にわたる壊死巣の確認が必要となる。④心房自由壁の線状凍結では、心房内腔からの凍結では心外膜面でのiceballの目視確認が可能であるが、心外膜面からの凍結では内膜面の目視が困難であるだけでなく心房内腔の血液による加温効果により不完全な凍結巣が作製される。

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  • 虚血心筋における不整脈発生のメカニズム

    研究課題/領域番号:16591417  2004年 - 2006年

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    菅野 重人, 清水 一雄, 新田 隆, 宮城 泰雄, 大森 裕也

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    配分額:3500000円 ( 直接経費:3500000円 )

    (実験系概略)C57BL/6J(WT/HTZ)を用いて作成した虚血モデルから得られた電気生理データ及び組織所見に関するデータを整理して総合的に解析し、科学的に証明し得た事実を抽出して検討を加えた。
    (不整脈に関する事実)心室心筋細胞において、Cx43の発現異常から心筋細胞間伝導遅延を生じる個体(Cx43+/一)の虚血モデルにおいて観察される不整脈は、ギャップ結合におけるチャンネル開閉不均衡が主たる要因であり、臨床的には致死性不整脈の一因と考えられる。虚血心筋においてこの現象が観察される場合、それは心筋傷害の拡散制御を目的とした生体防衛機能の発動と解釈することができる。ギャップ結合における物質の通過性を調節することによって心筋傷害発生後の生体の恒常性維持を図っていると考えることができる。
    (組織所見に関する事実)虚血周辺領域のギャップ結合におけるCx43の分布変化は速やかであり、ギャップ結合の細胞内移動によって隣接心筋細胞同士のコミュニケーションを遮断していると考えられる。この現象は偶発的に形成される組織学的な不整脈発生基質とは独立した要因と考えるべきであり、生体にとって不利益を生じる電気現象が生じても、傷害拡散防止を優先しようとする組織防衛機能によるものであると推察された。
    (臨床的意義)現在極めて困難とされる心臓手術の術中・術後における不整脈、とりわけ致死性不整脈の予防・制御に関し、ギャップ結合の物質透過性を標的とする対策に可能性が見出された。

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  • 左心房容量負荷モデルにおける心房細動の電気生理学的機序

    研究課題/領域番号:13671411  2001年 - 2003年

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    新田 隆, 宮城 泰雄, 菅野 重人, 田中 茂夫

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    配分額:3500000円 ( 直接経費:3500000円 )

    雑種成犬10頭を用いて、左房容量負荷と心房高頻度ペーシングモデルにおける左房容量と心房細動持続時間の経時的変化を検討した。さらに4-5週後に持続性心房細動の心外膜マッピングを行い、その電気生理学的特長を検討した。すなわち、鎖骨下動脈肺動脈短絡術による左房容量負荷を行い、さらに1週間後より刺激周期100msの左心房高頻度ペーシングを開始した。全頭において著明な左房拡大と進行性のうっ血性心不全がみられ、10頭中4頭は心不全にて死亡あるいはペーシングの維持が困難となった。残る6頭にて上記の検討を行った。高頻度ペーシング開始1週間後では、ペーシング中止後に数心拍の心房反復性興奮が認められ、2週間後では、心房反復性興奮が数秒間持続した。さらに経時的に経過を観察したところ、高頻度ペーシング開始4週間後では、ペーシング中止後に持続性心房細動が十分間以上維持された。右心耳と左心耳で経時的に記録した心房興奮周期は、常に左心耳が右心耳よりも短く、経過とともに短縮していった。持続性心房細動のマッピングでは、左右の上肺静脈から同時に出現する興奮周期の異なる巣状反復性興奮が観察された。この興奮は遅延伝導を伴って右心房に伝導していた。これらの所見は、ヒトの僧帽弁疾患に伴う心房細動の電気生理学的所見に極めて類似していることから、この新しい心房細動モデルは左房容量負荷に合併する心房細動の研究だけでなく、予防法と治療法の開発に有用であると考えられた。

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