Publications by authors named "Hidetaka Wakiyama"

Herein is reported a successful surgical case of aortic root replacement for aortic regurgitation in a patient with osteogenesis imperfecta. A 37-year-old male, who had been diagnosed as osteogenesis imperfecta of type IA, underwent mitral valve repair for mitral regurgitation. Severe aortic regurgitation developed four years after surgery.

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We describe 2 surgical cases of acute aortic type A dissection during pregnancy in women with Marfan syndrome. Both of them underwent emergency aortic root replacement under deep hypothermia; one patient was in her 21(st) week of pregnancy and the other was treated 1 day after a normal delivery. The patients experienced fair postoperative courses, but intrauterine fetus death was confirmed in the first case.

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Background: Previously, we have shown that magnesium supplemented potassium (DSA) cardioplegia and DSA containing diazoxide (DSA+DZX) significantly decrease apoptosis after ischemia. The mechanism for this enhanced cardioprotection was unknown, but we believed that alterations in signal transducers and activators of transcription (STATs) may play a role. To investigate this hypothesis, we examined the effects of DSA and DSA+DZX cardioplegia on STAT1/3 phosphorylation and DNA binding in the in situ blood perfused pig heart model.

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The case is reported of a 65-year-old male who required reoperation for early failure of a Freestyle stentless valve aortic root bioprosthesis implanted using the full root technique. The bioprosthesis had been implanted to treat annuloaortic ectasia associated with severe aortic regurgitation (AR). At 18 months postoperatively, a new diastolic murmur developed, though without complaint by the patient.

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Background: Recent studies have demonstrated that aging is associated with reduced tolerance to ischemia and that the aged (not senescent) female heart has greater susceptibility to ischemia as compared with the aged male heart. Previously, we have shown that ischemia can be modulated with cardioplegia in the male heart; however, efficacy in the female heart was unknown.

Methods: In this study, male and female mature (15 to 20 weeks) aged (>32 months) rabbit hearts (n = 134) were subjected to Langendorff perfusion.

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The surgical treatment for ischemic mitral regurgitation remains controversal. Ring annuloplasty results in recurrent mitral regurgitation in some cases. Strut chordal cutting is a new surgical procedure in addition to ring annuloplasty for ischemic mitral regurgitation.

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Necrosis and apoptosis differentially contribute to myocardial injury. Determination of the contribution of these processes in ischemia-reperfusion injury would allow for the preservation of myocardial tissue. Necrosis and apoptosis were investigated in Langendorff-perfused rabbit hearts (n = 47) subjected to 0 (Control group), 5 (GI-5), 10 (GI-10), 15 (GI-15), 20 (GI-20), 25 (GI-25), and 30 min (GI-30) of global ischemia (GI) and 120 min of reperfusion.

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Objective: This study was undertaken to evaluate the long-term results of mitral valve repair for mitral regurgitation.

Methods: Between 1991 and 2000, 301 patients with mitral regurgitation underwent mitral valve repair. There were 167 men and 134 women whose mean age was 56 +/- 14 years.

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Background: Recently, we have shown that the selective opening of mitochondrial ATP-sensitive potassium channels with diazoxide significantly decreases myocardial injury. The purpose of this study was to determine the effects of diazoxide on apoptosis and the mechanisms modulating apoptosis and myocardial injury in a blood-perfused model of acute myocardial infarction.

Methods: Pigs (32 to 42 kg) undergoing total cardiopulmonary bypass underwent left anterior descending coronary artery occlusion for 30 minutes.

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Background: Reactive oxygen and nitrogen species generated after reperfusion injury result in organ dysfunction. Peroxynitrite, a reactive nitrogen molecule produced from the reaction of superoxide anions and nitric oxide, is thought to be a causative agent in oxidative reperfusion injury. The aim of this study was to investigate the effects of a novel peroxynitrite decomposition catalyst (FP-15) in an acute myocardial ischemia/reperfusion model.

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Objective: Mitochondrial ATP-sensitive potassium channels have been proposed to be myoprotective. The relevance and specificity of this mechanism in cardiac surgery was unknown. The purpose of this study was to examine the effects of the mitochondrial potassium ATP-sensitive channel opener diazoxide on regional and global myocardial protection using a model of acute myocardial infarction.

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