127 research outputs found

    TAVIによって激変した大動脈弁狭窄症治療

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    Transcatheter aortic valve implantation(TAVI)has revolutionized the treatment of symptomatic severe aortic valve stenosis(AS). Severe AS can be lethal without intervention, but surgical replacement is contraindicated for older patients or patients with high risk for comorbidities. TAVI offers a less invasive option for the treatment of severe AS. TAVI is a viable life-extending treatment in these surgical high-risk groups

    Czochralski growth techniques of germanium crystals grown from a melt covered partially or fully by liquid B2O3

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    We propose two unique Czochralski (CZ) techniques for growing germanium (Ge) crystals with an extremely low dislocation density and high interstitial oxygen concentration ([Oi]) using boron oxide (B2O3) and a silica crucible. When a Ge melt is partially covered with liquid B2O3, but only on the outer region of the melt surface, germanium-oxide (GeO2)-related particles forming naturally in the melt are effectively dissolved by the liquid B2O3. The clean central portion of the melt produces dislocation-free undoped or Ga-doped Ge crystals. In addition, Ge crystals with [Oi] up to 6 x 10(17) cm(-3) can be grown from a melt fully covered by liquid B2O3 with added GeO2 powder. The reaction and transportation of oxygen atoms during the growth process using B2O3 was investigated, revealing that liquid B2O3 acts like a catalyst without heavy contamination of the growing Ge crystal by B and Si atoms. (C) 2011 Elsevier B.V. All rights reserved.JOURNAL OF CRYSTAL GROWTH. 360:47-51 (2012)journal articl

    Czochralski-growth of germanium crystals containing high concentrations of oxygen impurities

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    Oxygen-containing germanium (Ge) single crystals with low density of grown-in dislocations were grown by the Czochralski (CZ) technique from a Ge melt, both with and without a covering by boron oxide (B(2)O(3)) liquid. Interstitially dissolved oxygen concentrations in the crystals were determined by the absorption peak at 855 cm(-1) in the infrared absorption spectra at room temperature. It was found that oxygen concentration in a Ge crystal grown from melt partially or fully covered with B(2)O(3) liquid was about 10(16) cm(-3) and was almost the same as that in a Ge crystal grown without B(2)O(3). Oxygen concentration in a Ge crystal was enhanced to be greater than 10(17) cm(-3) by growing a crystal from a melt fully covered with B(2)O(3); with the addition of germanium oxide powder, the maximum oxygen concentration achieved was 5.5 x 10(17) cm(-3). The effective segregation coefficients of oxygen in the present Ge crystal growth were roughly estimated to be between 1.0 and 1.4.ArticleJOURNAL OF CRYSTAL GROWTH. 312(19):2783-2787 (2010)journal articl

    Decision-making using preload stress echocardiography

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    Aims Abnormal left ventricular diastolic response to preload stress can be an early marker of heart failure (HF). The aim of this study was to assess clinical course in patients with HF with preserved ejection fraction (HFpEF) who underwent preload stress echocardiography. In the subgroup analysis, we assessed the prognosis of patients with unstable signs during preload stress classified by treatment strategies. Methods and results We prospectively conducted preload stress echocardiographic studies between January 2006 and December 2013 in 211 patients with HFpEF. Fifty-eight patients had abnormal diastolic reserve during preload stress (unstable impaired relaxation: unstable IR). Of 58 patients with unstable IR, 19 patients were assigned to additional therapy by increased or additional therapy and 39 patients were assigned to standard therapy. Composite outcomes were prespecified as the primary endpoint of death and hospitalization for deteriorating HF. During a median period of 6.9 years, 19 patients (33%) reached the composite outcome. Unstable group with standard therapy had significantly shorter event-free survival than stable group. Patients with uptitration of therapy had longer event-free survival than those with standard therapy group after adjustment of laboratory data (hazard ratio, 0.20, 95% confidence interval, 0.05–0.90; P = 0.036); the 10 year event-free survival in patients with and without uptitration of therapy was 93% and 51%, respectively (P = 0.023). Conclusions Patients with unstable sign had significantly shorter event-free survival than patients with stable sign. After additional therapy, the prognosis of patients with unstable signs improved. This technique may impact decision-making for improving their prognosis

    3Dマッピングシステムを用いた両心房Stimulus-V mapによる順行性速伝導路入口部の解剖学的位置並び特徴の検討

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    Purpose Previous studies examined the right atrial (RA) input site of the antegrade fast pathway (AFp) (AFpI). However, the left atrial (LA) input to the atrioventricular (AV) node has not been extensively evaluated. In this study, we created three-dimensional (3-D) bi-atrial stimulus-ventricle (St-V) maps and analyzed the input site and characteristics of the AFp in both the RA and LA. Methods Forty-four patients diagnosed with atrial fibrillation or WPW syndrome were included in this study. Three-dimensional bi-atrial St-V mapping was performed using an electroanatomical mapping system. Sites exhibiting the minimal St-V interval (MinSt-V) were defined as AFpIs and were classified into seven segments, four in the RA (F, S, M, and I) and three in the LA (M1, M2, and M3). By combining the MinSt-V in the RA and LA, the AFpIs were classified into three types: RA, LA, and bi-atrial (BA) types. The clinical and electrophysiological characteristics were compared. Results AFpIs were most frequently observed at site S in the RA (34%) and M2 in the LA (50%), and the BA type was the most common (57%). AFpIs in the LA were recognized in 75% of the patients. There were no clinical or electrophysiological indicators for predicting AFpI sites. Conclusions Three-dimensional bi-atrial St-V maps could classify AFpIs in both the RA and LA. AFpIs in the LA were frequently recognized. There were no significant clinical or electrophysiological indicators for predicting AFpI sites, and 3-D bi-atrial St-V mapping was the only method to reveal the precise AFp input site

    Association of lower limb muscle mass and energy expenditure with visceral fat mass in healthy men

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    BACKGROUND: A high-calorie diet and physical inactivity, an imbalance between caloric intake and energy consumption, are major causes of metabolic syndrome (MetS), which manifests as accumulation of visceral fat and insulin resistance. However, the lifestyle-related factors associated with visceral fat mass in healthy men are not fully understood. METHODS: We evaluated visceral fat area (VFA), skeletal muscle mass, caloric intake, and energy expenditure in 67 healthy male participants (mean age, 36.9 ± 8.8 years; body mass index 23.4 ± 2.5 kg/m(2)). RESULTS: Multiple regression analysis showed that the total skeletal muscle mass (P < 0.001) were negatively and age (P < 0.001) were positively associated with VFA. Lower limb muscle mass (P < 0.001) was strongly associated with VFA. However, total caloric intake, total energy expenditure, and energy expenditure during exercise were not associated with VFA. CONCLUSIONS: Skeletal muscle mass especially lower limb muscle mass negatively contributes to visceral fat mass in healthy men. Therefore, maintaining lower limb muscular fitness through daily activity may be a useful strategy for controlling visceral obesity and metabolic syndrome

    Lp(a) on aortic valve calcification

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    Aortic valve calcification (AVC), which causes aortic stenosis (AS), is more common in elderly persons. Controlling for conventional risk variables did not, however, reduce the incidence of AS. Thus, residual risk factors of AS should be identified. We enrolled 513 patients who underwent coronary angiography with computed tomography because of suspicion of coronary artery disease (CAD) or ruling out of CAD before aortic valve replacement. Calcium volume was calculated with a commercially available application. Conventional and lipid-related risk factors including serum levels of Lp(a) were evaluated for all patients. Calcium volume and Lp(a) levels were significantly higher in patients who underwent aortic valve replacement than in those who did not. A single regression analysis showed that the calcium volume was positively associated with age and the Lp(a) levels and negatively associated with the estimated glomerular filtration rate. No statistical significance was observed for other risk factors, including oxidized low-density lipoprotein, omega-3 fatty acids levels. The multiple regression analysis revealed that age (P < 0.001), female sex (P < 0.05), Lp(a) (P < 0.01), and hemoglobin A1c (P < 0.01) were determinants of the calcium volume. The area under the curve in receiver operating characteristic analysis of Lp(a) for implementation of AVR was 0.65 at an Lp(a) cut-off level of 16 mg/dL. In conclusion, the serum Lp(a) level is a potent risk factor of AVC in patients with high risk of atherosclerosis

    Optimal medical therapy to diuretics

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    Background : We sought to compare the outcomes of patients receiving combination therapy of diuretics and neurohormonal blockers, with a matched cohort with monotherapy of loop diuretics, using real-world big data. Methods : This study was based on the Diagnosis Procedure Combination database in the Japanese Registry of All Cardiac and Vascular Datasets (JROAD-DPC). After exclusion criteria, we identified 78,685 patients who were first hospitalized with heart failure (HF) between April 2015 and March 2017. Propensity score (PS) was estimated with logistic regression model, with neurohormonal blockers (angiotensin-converting enzyme inhibitor : ACEi or angiotensin receptor blocker : ARB, β-blockers and mineralocorticoid receptor antagonists : MRA) as the dependent variable and 24 clinically relevant covariates to compare the in-hospital mortality between monotherapy of loop diuretics and combination therapies. Results : On PS-matched analysis, patients with ACEi / ARB, β-blockers, and MRA had lower total in-hospital mortality and in-hospital mortality within 7 days, 14 days and 30 days. In the sub-group analysis, regardless of clinical characteristics including elderly people and cancer, patients treated with a combination of loop diuretics and neurohormonal blockers had significantly lower in-hospital mortality than matched patients. Conclusions : Our data indicate the benefits of guideline-directed medical therapy to loop diuretics in the management of HF

    Effects of Esaxerenone on Diabetes-Induced Endothelial Dysfunction

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    Aims: Pharmacological blockade of mineralocorticoid receptors (MRs) is a potential therapeutic approach to reduce cardiovascular complications since MRs play a crucial role in cardiovascular regulation. Recent studies suggest that MR antagonists affect several extrarenal tissues, including vessel function. We investigated the effect of a novel nonsteroidal selective MR blocker, esaxerenone, on diabetes-induced vascular dysfunction. Methods: Diabetes was induced by a single dose of streptozotocin in 8-week-old male C57BL/6 mice. Esaxerenone (3 mg/kg/day) or a vehicle was administered by gavage to diabetic mice for 3 weeks. Metabolic parameters, plasma aldosterone levels, and parameters related to renal function were measured. Endothelium-dependent or -independent vascular responses of the aortic segments were analyzed with acetylcholine or sodium nitroprusside, respectively. Human umbilical vein endothelial cells (HUVECs) were used for the in vitro study. Results: Induction of diabetes elevated plasma aldosterone level (P<0.05) and impaired endothelium-dependent vascular relaxation (P<0.05). The administration of esaxerenone ameliorated the endothelial dysfunction (P<0.01) without the alteration of metabolic parameters, blood pressure, and renal function. Esaxerenone improved the eNOSSer1177 phosphorylation in the aorta obtained from diabetic mice (P<0.05) compared with that in the vehicle-treated group. Furthermore, a major MR agonist, aldosterone, decreased eNOSSer1177 phosphorylation and increased eNOSThr495 phosphorylation in HUVECs, which recovered with esaxerenone. Esaxerenone ameliorated the endothelium-dependent vascular relaxation caused by aldosterone in the aortic segments obtained from C57BL/6 mice (P<0.001). Conclusion: Esaxerenone attenuates the development of diabetes-induced endothelial dysfunction in mice. These results suggest that esaxerenone has potential vascular protective effects in individuals with diabetes
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