Yutaka Ishibashi

Shimane University, Matsu, Shimane Prefecture, Japan

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Publications (83)186.65 Total impact

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    ABSTRACT: BACKGROUND: Recent reports revealed the presence of acquired von Willebrand syndrome type 2A in patients with aortic valve stenosis (AS). von Willebrand factor (vWF) has been shown to play a vital role in platelet adhesion. Therefore, we measured the platelet retention rates, which reflect platelet adhesion, in patients with severe AS. METHODS: In addition to echocardiography, routine blood screening tests were performed and the platelet retention rates were measured using collagen-coated bead columns in 21 patients with severe AS and in 21 control subjects. RESULTS: Patients with severe AS showed the maximum aortic valve pressure gradients of 110.9±22.7mmHg, and effective orifice areas of 0.59±0.20cm(2). The results of routine blood tests in patients with severe AS were comparable to those of control subjects; however, the platelet retention rates in the AS patients (7.3±5.0%) were significantly lower than those in control subjects (30.5±11.8%, p<0.001). A significant negative correlation was observed between maximum aortic valve pressure gradients and platelet retention rates (r=-0.81, p<0.001). In 8 patients with severe AS, the platelet retention rates increased from 5.8±3.6% to 16.0±2.4% after aortic valve replacement (p<0.001). CONCLUSION: These findings suggest that impairment of platelet retention rate is seen in almost all patients with severe AS. Clinicians should be aware of the possibilities of vWF-mediated platelet dysfunction and bleeding tendency in patients with severe AS.
    Journal of Cardiology 05/2013; · 2.30 Impact Factor
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    ABSTRACT: Although rare, bloodstream infections caused by Aeromonas tend to be very severe and progress rapidly. We report a case of an 81-year-old man with fetal septicemia and endotoxin shock caused by Aeromonas hydrophila. The patient had dilated cardiomyopathy, paroxysmal atrial fibrillation, interstitial pneumonitis and renal dysfunction was admitted to our hospital with chest pain and dyspnea. Transthoracic echocardiography demonstrated impaired left ventricular wall motion and severe mitral regurgitation due to tethering. Cardiac catheterization revealed severe stenotic lesions in the left anterior descending artery and the right coronary artery. Surgery for coronary artery bypass grafts and mitral annuloplasty were performed. However, 2 days after surgery, he suddenly developed a high-grade fever and his hemodynamics deteriorated rapidly. His blood cultures revealed gram-negative Bacillus and the endotoxin concentration in the blood was elevated. Despite intensive support efforts, the patient died 1 day after the sudden change. His blood culture revealed A. hydrophila. Whenever Aeromonas is found in a patient's bloodstream, clinicians should start appropriate and intensive treatment immediately.
    The American journal of case reports. 01/2012; 13:72-4.
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    ABSTRACT: Takayasu arteritis and ulcerative colitis are immune-mediated inflammatory diseases; genetic factors are assumed to play an important role in the pathogenesis of these 2 diseases. However, the coexistence of these 2 diseases has rarely been reported. In this report, we present a rare case of a 29-year-old man with a 4 years history of ulcerative colitis who developed Takayasu arteritis. He was found to carry the following human leukocyte antigens (HLA): A11, A24, B52, B62, DR4, and DR9. We present a case report and review of the pertinent literature on serological analysis of HLA haplotype of the patients who exhibit both these diseases. In patients with both Takayasu arteritis and ulcerative colitis, high frequency of HLA-A24, B52, and DR 2 is observed. The pathological relevance of HLA-A24, B52, and DR2 to concomitant Takayasu arteritis and ulcerative colitis requires further investigation.
    Medical science monitor: international medical journal of experimental and clinical research 07/2011; 17(7):CS81-4. · 1.36 Impact Factor
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    ABSTRACT: Aortic valve sclerosis, calcification, and stenosis are common in the elderly. Increased life expectancy has resulted in a growing population of elderly people, with a corresponding increase in the number of patients with these degenerative aortic valve diseases. We report a case of severe aortic stenosis in an 82-year-old woman with bleeding due to colonic angiodysplasia. The patient presented with anemia unexpectedly before her aortic valve replacement. Colon fiberscopy revealed that colonic angiodysplasia was responsible for the bleeding. The lesion was treated with endoscopic clipping before the successful aortic valve replacement. Additionally, her immunoblot analysis detected a decrease of large molecular weight multimers of von Willebrand factor. The relationship between aortic valve stenosis, acquired von Willebrand disease and gastrointestinal bleeding in elderly patients is known as Heyde syndrome. Clinicians should be aware of the possibilities of acquired von Willebrand disease and gastrointestinal bleeding from angiodysplasia in patients with aortic valve stenosis.
    Medical science monitor: international medical journal of experimental and clinical research 09/2010; 16(9):CS107-9. · 1.36 Impact Factor
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    ABSTRACT: We report the case of a 62-year-old woman with Acinetobacter baumannii bacteremia. She was admitted to our hospital with ventricular tachycardia and was subsequently diagnosed with idiopathic ventricular tachycardia, with no structural heart disease. However, 12 days after admission, she suddenly developed a high-grade fever with chills and diarrhea. Her blood cultures revealed A. baumannii, and the patient was treated with meropenem and amikacin sulfate. Yet, the patient's symptoms and clinical signs became worse. We then began to administer a large quantity of intravenous ampicillin-sulbactam, and the patient improved dramatically. Although rare, bloodstream infection caused by A. baumannii tends to be severe. Therefore, when A. baumannii is found in a patient's bloodstream, clinicians should start appropriate treatment immediately and should recall ampicillin-sulbactam as a sensible option for treatment.
    Japanese journal of infectious diseases. 11/2009; 62(6):461-3.
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    ABSTRACT: A 66-year-old Japanese woman was urgently referred to our hospital. Two days prior to admission, her general practitioner began to administer prednisolone for treatment of a diagnosis of polymyalgia rheumatica. At the time of admission, laboratory results indicated multiorgan failure with rhabdomyolysis. Abdominal ultrasonography and computed tomography revealed a tumor in the right adrenal gland. On the same day, we measured serum and urine cathecholamines, which were markedly elevated. Additionally, magnetic resonance imaging revealed an adrenal mass and metaiodobenzylguanidine scintigraphy showed labeling of the tumor. Then, the patient underwent surgical resection of the tumor via laparoscopy. Histological examination confirmed the diagnosis of pheochromocytoma. One week after the operation, serum and urinary catecholamine levels returned to normal. The patient was discharged 10 days after the operation, and has remained stable at home. This report indicates that steroid should be avoided if possible in patients with pheochromocytoma. Furthermore, pheochromocytoma should be recalled as a differential diagnosis whenever patients take a sudden turn for the worse, or have acute uncontrollable hypertension following steroid administration and/or whenever patients present with unexplained rhabdomyolysis.
    International journal of cardiology 02/2009; 146(2):e41-5. · 7.08 Impact Factor
  • CVD Prevention and Control 01/2009; 4.
  • CVD Prevention and Control 01/2009; 4.
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    ABSTRACT: Activation of inducible nitric oxide synthase (iNOS) has been reported in congestive heart failure (CHF) conditions. However, it is unknown whether activation of iNOS affects prognosis of CHF patients. We prospectively studied the influence of activation of iNOS in the forearm on the outcome of CHF patients. Forearm blood flow (FBF) responses to 3 doses of acetylcholine (ACh) and nitroglycerin (NTG), and 4 doses of a selective iNOS inhibitor (aminoguanidine: Amn) and a nonselective NOS inhibitor (L-NMMA) were examined using plethysmography in 68 patients with CHF from idiopathic dilated cardiomyopathy. Plasma brain natriuretic peptide (BNP) and tumor necrosis factor-alpha (TNF-alpha) were also measured in all patients. During the mean follow-up period of 3.8 years, 25 patients were hospitalized for worsening heart failure and 9 of these patients died. Patients with adverse events had a diminished vasodilator response to ACh (P < .001) compared to patients without adverse events. Amn significantly decreased FBF (P < .001) in patients with adverse events, but not in patients without adverse events. FBF responses to NTG and L-NMMA were not significantly different between the 2 groups. When grouped by maximum FBF responses to each drug above and below the median value, multivariate Cox proportional hazards model analyses for cardiac event showed a significance in the FBF response to Amn (adjusted hazard ratio 5.89, P < .001). FBF responses to maximum dose of Amn significantly correlated with BNP and TNF-alpha levels (both P < .001). CHF patients with vascular iNOS activation, as demonstrated by a greater vasoconstrictor response to Amn, had poor outcomes. Activation of iNOS in peripheral vessels, associated with proinflammatory cytokines in accordance to the severity of heart failure, is a marker for, or contributes to, adverse events in patients with CHF.
    Journal of cardiac failure 11/2008; 14(9):724-31. · 3.25 Impact Factor
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    ABSTRACT: We report a case of a 60-year-old woman. She was transferred from a local hospital to our cardiovascular medicine department with a diagnosis of infectious endocarditis due to Staphylococcus lugdunensis. Transthoracic echocardiograph confirmed the presence of large vegetations on the native aortic and mitral valve, and subsequent severe regurgitation due to the aortic and mitral valve destruction. Emergent operation was performed and patient's life was barely rescued. However, S. lugdunensis belongs to coagulase-negative staphylococci, which are generally regarded as relatively avirulent bacterium, the endocarditis caused by S. lugdunensis can be invasive and often resembles endocarditis due to Staphylococcus aureus. Therefore, whenever this organism is found in patients with endocarditis, early surgical treatment of the infected valve should be considered.
    International journal of cardiology 09/2008; 137(1):e15-7. · 7.08 Impact Factor
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    ABSTRACT: Long-term administration of nicorandil has been shown to improve outcomes through cardioprotective effects in patients with coronary artery disease. To identify the mechanisms responsible for these effects, this study examined the impact of long-term nicorandil administration on endothelial function, systemic inflammatory markers, and oxidative stress in patients with cardiovascular risk factors. Fifty-three patients were assigned to receive either nicorandil therapy (15 mg/day; n = 26) (nicorandil group) or usual care (n = 27) (nonnicorandil group). All study participants underwent flow-mediated vasodilatation (FMD) of the brachial artery 1 month before treatment, just before treatment, and at 3, 6, and 12 months following treatment. At identical time points, serum levels of malondialdehyde-modified low-density lipoprotein (MDA-LDL) and high-sensitivity C-reactive protein (hs-CRP) were collected. Compared with the nonnicorandil group, the nicorandil group demonstrated significantly increased FMD at 12 months, a finding not replicated for endothelium-independent vasodilatation with nitroglycerine. Analysis of biochemical markers revealed significantly reduced MAD-LDL levels in the nicorandil group at 12 months, as compared to slightly increased MAD-LDL levels in the nonnicorandil group. Significant reductions in hs-CRP levels were also noted at 6 and 12 months in the nicorandil group, while no change was found in the nonnicorandil group. Results demonstrated that long-term nicorandil therapy is associated with gradual improvements in endothelial function. Our findings also suggest that nicorandil treatment may result in cardiovascular protection through pleiotropic effects including reductions in oxidative injury and systemic inflammation.
    Journal of Cardiovascular Pharmacology 04/2008; 51(3):311-6. · 2.38 Impact Factor
  • 01/2008: pages e77-80; , ISBN: 1874-1754 (Electronic)
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    ABSTRACT: Although links have been found between microorganisms and cardiovascular diseases, the role of hepatitis C virus (HCV) infection in the pathogenesis of arteriosclerosis and cardiovascular events is unclear. The primary objective of this research was to examine whether HCV infection is associated with increased aortic stiffness and cardiovascular events in chronic hemodialysis patients. A prospective cohort study was conducted in 94 dialysis outpatients from October 2002 to October 2004. Measurements included carotid-femoral pulse wave velocity (PWV), echocardiographic parameters, serum HCV-RNA (positive in 17 patients), and several items of biochemical data. Multiple logistic regression and the Cox proportional hazard model were used to assess independent determinants of high aortic PWV (> or =10.0 m/sec, mean) and cardiovascular events (including cerebral and peripheral vascular events), adjusting for several risk factors and duration of dialysis. The HCV-positive group had higher aortic PWV and lower serum cholesterol levels. Multivariate analysis indicated mean blood pressure, hemoglobin A1c and HCV viremia to be independent determinants of high PWV. During the follow-up period, 13 patients suffered from cardiovascular events. Prevalence of the diseases at baseline, pulse pressure, left ventricular mass index, HCV viremia and aortic PWV were associated with cardiovascular events. The Kaplan-Meier analysis indicated a significant difference in event-free rates between HCV-positive and HCV-negative patients. HCV infection is closely associated with increased aortic stiffness and cardiovascular event in dialysis patients.
    Journal of nephrology 01/2008; 21(3):345-53. · 2.02 Impact Factor
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    ABSTRACT: A 36-year-old man with diabetes mellitus on dialysis due to renal failure was admitted to our hospital for cardiovascular examination. His echocardiogram demonstrated marked left ventricular hypertrophy. A muscle biopsy revealed the presence of a mitochondrial DNA mutation (A3243G), leading to the diagnosis of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes). Although it is rare for patients with mitochondrial disease to be referred to a cardiologist, mitochondrial cardiomyopathy must remain in the differential diagnosis of hypertrophic cardiomyopathy of unknown origin.
    International journal of cardiology 10/2007; 129(3):e77-80. · 7.08 Impact Factor
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    ABSTRACT: We report a case of a 66-year-old woman admitted to our hospital for examination and treatment of uterine and rectal prolapse, pleural and pericardial effusion, and ascites. On further examination, she was diagnosed with hypothyroidism. Test results showed markedly elevated concentrations of serum carcinoembryonic antigen (CEA) and carbohydrate antigen 125 (CA 125). We consequently performed multiple imaging studies, none of which detected a malignancy. Hormonal replacement therapy with levothyroxine was started, and the pleural and pericardial effusion and ascites gradually abated. Concentrations of serum CEA and CA125 also decreased gradually after therapy with levothyroxine. These findings indicate that in patients with hypothyroidism, elevated CEA and CA125 levels do not necessarily indicate malignancy. Conversely, in any patient with elevated serum CEA and/or CA125, hypothyroidism should be considered in the differential diagnosis.
    The American Journal of the Medical Sciences 07/2007; 333(6):387-9. · 1.33 Impact Factor
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    ABSTRACT: SUMMARY1. The present study was designed to test the hypotheses whether platelet degranulation across the coronary bed is detectable during non-ischaemic periods in patients with vasospastic angina (VSA) and whether the exogenous nitric oxide (NO) donor nitroglycerin (GTN) is able to modify platelet degranulation, reflecting an impaired endothelial production of NO.2. We studied 13 patients with VSA and 10 controls. The time course of coronary sinus (CS) plasma 5-hydroxytryptamine (5-HT) levels was evaluated every 4 h before and after intravenous infusion of GTN over a period of 40 h. Coronary sinus plasma 5-HT levels were significantly higher at any measured time point in patients with VSA compared with control and were significantly decreased in patients with VSA following treatment with GTN, but not in controls. Femoral artery plasma 5-HT levels remained almost constant throughout the study. The ratio of CS:aorta 6-keto-prostaglandin F1 was significantly and inversely correlated with the transcardiac plasma 5-HT difference only in patients with VSA (r=−0.68; P < 0.02; n= 13).3. The time course of CS 5-HT levels confirmed significant platelet degranulation across the coronary bed supplied by the spasming artery in patients with VSA and this was modified by GTN. The present data suggest that platelet degranulation occurs during non-ischaemic periods in patients with VSA and that prostacyclin biosynthesis may be a compensatory response to an impaired endothelial release of NO, limiting the degree of the effects of platelet degranulation.
    Clinical and Experimental Pharmacology and Physiology 06/2007; 25(12):999 - 1003. · 2.16 Impact Factor
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    ABSTRACT: There are few reports of cardiac involvement in patients with Kugelberg-Welander disease. We report a case of a 51-year-old man with Kugelberg-Welander disease who presented with syncope. His electrocardiogram showed complete right bundle branch block and transient complete atrioventricular block without escape rhythm. He was successfully treated with emergency temporary pacing followed by permanent pacemaker implantation. In this report, we review the relevant literature and argue that patients with Kugelberg-Welander disease should be evaluated regularly for cardiac disease.
    The American Journal of the Medical Sciences 01/2007; 332(6):354-6. · 1.33 Impact Factor
  • Journal of Cardiac Failure - J CARD FAIL. 01/2007; 13(6).
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    ABSTRACT: 1. Previous clinical studies with prostaglandin I(2) (PGI(2)) analogue beraprost sodium suggested the potential effects on protection of cardiovascular events in patients with peripheral artery disease. Although the mechanism is not well known, experimental studies have shown protective effects of endothelial cells. This study was designed to examine the effects of beraprost sodium on vascular endothelial function in the forearm of patients with coronary artery disease. 2. Beraprost sodium (120 microg/day) was orally administered to 14 coronary artery disease patients for 4 weeks and then stopped for 4 weeks. Eleven control patients did not receive beraprost sodium treatment. Reactive hyperemia was induced in the forearm, endothelium-dependent vasodilatation was assessed by plethysmography, and urinary 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) was measured at baseline, 4 weeks and 8 weeks. 3. Both groups had similar reactive hyperemic responses at baseline. In the control group, reactive hyperemic response and urinary 8-iso-PGF(2alpha) remained unchanged for 8 weeks. In the beraprost group, maximum forearm blood flow increased significantly (P = 0.01) after 4 weeks of treatment and returned to baseline at 8 weeks. Duration of hyperemia increased significantly (P = 0.003) after 4 weeks, and remained greater than baseline at 8 weeks (P = 0.02). Urinary 8-iso-PGF(2alpha) decreased significantly (P = 0.03) after 4 weeks, and tended to be lower at 8 weeks (P = 0.07). Changes in reactive hyperemia correlated weakly but significantly with changes in 8-iso-PGF(2alpha) (P < 0.001). 4. Beraprost sodium decreased oxidative stress and improved forearm endothelium-dependent vasodilatation in coronary artery disease patients. The favorable effects on vascular endothelium could potentially lead to a decrease in vascular events.
    Clinical and Experimental Pharmacology and Physiology 05/2006; 33(4):381-7. · 2.16 Impact Factor
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    ABSTRACT: Peripheral vascular endothelial dysfunction is an independent predictor of cardiovascular events, and can be assessed noninvasively by measuring reactive hyperemia, either by vascular ultrasound measurement of flow-mediated vasodilatation or, less commonly, by measurement of blood flow using plethysmography. In the present study reactive hyperemia was measured using plethysmography in healthy subjects with multiple cardiovascular risk factors. Reactive hyperemia was measured following 5-min occlusion of the upper arm in 449 healthy subjects (302 men, 147 women, age range 20-70 years) with (n=352) and without (n=97) risk factors such as smoking, hypertension, diabetes mellitus, hypercholesterolemia, obesity, family history of cardiovascular disease, and menopause. Maximum blood flow and minimum vascular resistance in reactive hyperemia did not differ between subjects with and without risk factors regardless of gender. Duration of reactive hyperemia, however, was significantly shorter in subjects with risk factors. Age-adjusted mean value of duration of reactive hyperemia was significantly smaller in men with a smoking habit, diabetes mellitus, hypercholesterolemia or obesity, and in women with smoking habit, hypertension, diabetes mellitus or obesity. The number of risk factors significantly correlated with the duration of reactive hyperemia in both men (r=-0.56, p<0.001) and women (r=-0.62, p<0.001), suggesting that endothelial dysfunction increases with the number of risk conditions clustering in a single individual. Duration of reactive hyperemia reflects cardiovascular risk factors and decreases with the number of risk conditions. These findings suggest that the duration of reactive hyperemia measured with plethysmography is potentially useful for assessing endothelial dysfunction.
    Circulation Journal 02/2006; 70(1):115-23. · 3.58 Impact Factor