Publications by authors named "Hiroki Katoh"

Sporangimicins A-D (1-4), four anomeric pairs of diacyl disaccharides that represent a new metabolite class, were discovered from the culture extract of an actinomycete Pseudosporangium sp. RD061809. Compounds 1-4 caused peak separation in the HPLC chromatogram and partial duplication of the NMR resonances by anomeric interconversion of a maltose core modified at the two sugar 6-positions with an isobutanoyl and a methyl-branched long-chain dienoyl groups.

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Background: The significance of incorporating regional functional heterogeneity assessment by liver scintigraphy into the calculation of the future liver remnant has been reported. However, liver scintigraphy entails additional costs and radiation exposure. Nevertheless, studies describing when liver scintigraphy demonstrates an actual benefit over computed tomography liver volumetry are lacking.

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Objectives: L-Carnitine, a quaternary amine, improves fatty acid metabolism in the heart and has anti-inflammatory effects. Several studies have reported the efficacy of L-carnitine for the prophylaxis of arrhythmia. We assessed the clinical effectiveness of L-carnitine in preventing postoperative atrial fibrillation (POAF) in aortic valve surgery.

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Atrial metabolic disturbance contributes to the onset and development of atrial fibrillation (AF). Autophagy plays a role in maintaining the cellular energy balance. We examined whether atrial gene expressions related to fatty acid metabolism and autophagy are altered in chronic AF and whether they are related to each other.

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Proteasomes are essential protease complexes that maintain cellular homeostasis, and aberrant proteasomal activity supports cancer development. The regulatory mechanisms and biological function of the ubiquitin-26S proteasome have been studied extensively, while those of the ubiquitin-independent 20S proteasome system remain obscure. Here, we show that the cap 'n' collar (CNC) family transcription factor NRF3 specifically enhances 20S proteasome assembly in cancer cells and that 20S proteasomes contribute to colorectal cancer development through ubiquitin-independent proteolysis of the tumor suppressor p53 and retinoblastoma (Rb) proteins.

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Objectives: The slope in the preload recruitable stroke work relationship is a highly linear, load-insensitive contractile parameter. However, the perioperative change of the slope has not been reported before. We examined the perioperative slope from a steady-state single beat in patients with functional mitral regurgitation and assessed the correlation with brain natriuretic peptide (BNP) levels.

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Objectives: While it was reported that patients with residual moderate mitral regurgitation (MR) after surgical aortic valve replacement (SAVR) had a poorer prognosis than those without it, the risk factors for residual MR have not been fully elucidated. The aim of the study was to evaluate risk factors for residual MR after SAVR.

Methods: Of the 222 patients who underwent isolated SAVR from 2001 to 2018, 33 (11 men; age: 74 ± 7 years) had functional moderate MR before surgery.

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Transvalvular leakage (TVL) of a prosthetic heart valve is not negligible regurgitant flow in patients with critically low contractile function. Although the opening function of prosthetic valves has been reported, its closing function is not well understood. A man in his 70 s had a history of mitral valve replacement (MVR) with a Magna Mitral® valve for ischemic mitral valve regurgitation.

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Ideally, an annuloplasty ring's shape should be changed intraoperatively if mitral valve repair is unsuccessful because of a short coaptation length or systolic anterior motion. Several post-implantation adjustable rings have been developed, but they are not freely deformable and are unsuitable for asymmetric repair of the valvular annulus. We developed a novel thermally deformable mitral annuloplasty ring to address these problems and assessed the ring's mechanical properties and its effect on the mitral valve anatomy.

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Antiphospholipid syndrome (APS) is a complex autoimmune disease often related to systemic lupus erythematosus. Although adequate anticoagulation is important for APS patients during cardiopulmonary bypass, clotting tests can be potentially misleading due to antiphospholipid antibodies. We performed cardiac surgery safely in two APS patients under anticoagulation monitoring determined using preoperative heparin titration.

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Background: Although non-transplant surgical interventions for non-ischemic dilated cardiomyopathy (NIDCM) are relatively effective, their feasibility and limitations have not been fully elucidated. The aim of this study was to define the feasibility and limitations of mitral valve repair, with or without surgical ventricular reconstruction for patients with NIDCM in terms of postoperative low cardiac output syndrome (LOS).

Methods: Twenty non-transplant candidates (aged 57±13 years) with NIDCM and significant mitral regurgitation had undergone mitral valve repair combined with submitral procedures.

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Accumulated evidence suggests a physiological relationship between the transcription factor NRF3 (NFE2L3) and cancers. Under physiological conditions, NRF3 is repressed by its endoplasmic reticulum (ER) sequestration. In response to unidentified signals, NRF3 enters the nucleus and modulates gene expression.

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Background: Post-operative atrial fibrillation (POAF) frequently occurs after cardiac surgery. However, the mechanisms of POAF have not been fully elucidated. We aimed to examine whether pre-operative atrial gene expression related to cardiac metabolism is changed in patients with POAF.

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Purpose: The progression of left ventricular (LV) remodeling and subsequent mitral valve tethering impair the results of reduction annuloplasty for ischemic mitral regurgitation (MR).

Methods: We studied 90 patients who underwent surgical repair of ischemic MR between 1999 and 2013 according to our surgical strategy adding submitral and ventricular procedures to annuloplasty as follows: annuloplasty alone (stage 1, n = 30), additional papillary muscle approximation (PMA) for progression of tethering (stage 2, n = 26), and additional left ventriculoplasty with PMA for progression of LV remodeling and tethering (stage 3, n = 34).

Results: The preoperative New York Heart Association (NYHA) functional classes (2.

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Purpose: Transcatheter aortic valve replacement (TAVR) has emerged as a therapeutic option for severe aortic valvular stenosis (AS). To determine the indication for TAVR, it is mandatory to clarify the characteristics of the patients who were judged as inoperable for conventional aortic valve replacement (cAVR).

Methods: Of 185 patients newly diagnosed as severe AS from March 2010 to April 2011, we studied the characteristics of 61 (33%) patients (mean age, 86 ± 8 years) who were judged as inoperable.

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Pantothenate kinases (CoaAs) catalyze the phosphorylation of pantothenate in the first step of the coenzyme A (CoA) biosynthetic pathway. These bacterial enzymes have been categorized into 3 types, the prokaryotic type I, II, and III CoaAs. Bacteria typically carry a single CoaA gene on their genome, but Bacillus subtilis possesses 2 proteins homologous to type I and III CoaAs, known as BsCoaA and BsCoaX, respectively.

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Pantothenate synthetase (PanC) and pantothenate kinase which function in the canonical coenzyme A (CoA) biosynthetic pathway cannot be found in most archaea. COG1829 and COG1701 intrinsic to archaea were proposed as the candidate proteins for producing 4'-phosphopantothenate instead, and the COG1701 protein from Methanosarcina mazei was assigned as PanC. Meanwhile, the Thermococcus kodakarensis COG1829 and COG1701 proteins were biochemically identified as novel enzymes, i.

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Objective: The aim of this study was to evaluate detailed vessel response after everolimus-eluting stents (EES) implantation in human de novo coronary lesions by optical coherence tomography (OCT).

Design, Setting And Patients: Between November 2008 and October 2009, 25 patients (14 men, 65.5±8.

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Levels of three coenzyme A (CoA) molecular species, i.e., nonesterified CoA (CoASH), acetyl-CoA, and malonyl-CoA, in fasted and fed rat tissues were analyzed by the acyl-CoA cycling method which makes detection possible at the pmol level.

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Background: Sirolimus-eluting stents (SES) have incomplete neointimal coverage at 6-month follow up as determined with optical coherence tomography (OCT). The long-term detailed changes of neointima in SES remains to be clarified.

Methods And Results: Serial changes in neointimal coverage of SES from 6 months to 12 months using OCT were examined.

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Off-pump coronary artery bypass grafting (CABG) has been rapidly increased, because of its less invasiveness with low complications. However, graft patency rate highly depends on the operators' capability due to technical difficulties. The SPY system, based on the fluorescence of indocyanine green, is an innovative device that permits validation of graft patency intra-operatively.

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Objective: Impaired cerebrovascular reactivity (CVR) to vasodilating agents is a predictor of the onset and prognosis of ischemic stroke. It is realized that the CVR improves or worsens when measured periodically during the clinical course in medically treated patients with occlusive cerebrovascular disease. In these patients, we investigated the possible relationship between the interval change in CVR and that in systemic blood pressure (BP).

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Objectives: Whereas transplantation of insulin-secreting pancreatic islets may provide long-term control of glucose metabolism in patients with diabetes mellitus, transplant rejection remains a problem. In this study, we tried pretreatment with frozen pancreatic tissue in a rat model of islet cell transplantation to determine whether induction of immune tolerance is feasible.

Methods: Isolated islet cells from Wistar rats were transplanted into the spleen of recipient rats that were sensitized and rats that were not sensitized with frozen pancreatic tissue.

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