Kazuya Yonezawa

Kyōto Medical Center, Kyoto, Kyoto-fu, Japan

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Publications (11)40.39 Total impact

  • Article: Report from the Japanese registry of CPR for in-hospital cardiac arrest (J-RCPR).
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    ABSTRACT: In-hospital cardiopulmonary arrest (CPA) is an important issue, but data in Japan are limited. To investigate in-hospital CPA, we conducted a prospective multicenter observational registry of in-hospital CPA and resuscitation in Japan (J-RCPR). During January 2008 to December 2009, patients were registered from 12 participating hospitals. All patients, visitors and employees within the facility campus who experience a cardiopulmonary resuscitation event defined as either a pulseless or a pulse with inadequate perfusion requiring chest compressions and/or defibrillation of ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) were registered. Data were collected in 6 major categories of variables: facility data, patient demographic data, pre-event data, event data, outcome data, and quality improvement data. Data for 491 adults were analyzed. The prevalence of pulseless VT/VF as first documented rhythm was 28.1%, asystole was 29.5% and pulseless electrical activity was 41.1%. Immediate causes of event were arrhythmia 30.6%, acute respiratory insufficiency 26.7%, and hypotension 15.7%. Return of spontaneous circulation was 64.7%; the proportion of survival 24h after CPA was 49.8%, the proportion of survival to hospital discharge was 27.8% and proportion of favorable neurological outcome at 30 days was 21.4%. This is the first report of the registry for in-hospital CPA in Japan and shows that the registry provides important observational data.
    Circulation Journal 03/2011; 75(4):815-22. · 3.77 Impact Factor
  • Article: [A study of the transport of three dimensional medical images to remote institutions for telediagnosis].
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    ABSTRACT: Using a 3D-imaging-create-function server and network services by IP-VPN, we began to deliver 3D images to the remote institution. An indication trial of the primary image, a rotary trial of a 3D image, and a reproducibility trial were studied in order to examine the practicality of using the system in a real network between Hakodate and Sapporo (communication distance of about 150 km). In these trials, basic data (time and receiving data volume) were measured for every variation of QF (quality factor) or monitor resolution. Analyzing the results of the system using a 3D image delivery server of our hospital with variations in the setting of QF and monitor resolutions, we concluded that this system has practicality in the remote interpretation-of-radiogram work, even if the access point of the region has a line speed of 6 Mbps.
    Nippon Hoshasen Gijutsu Gakkai zasshi 01/2011; 67(1):32-40.
  • Article: Exposure to pressure stimulus enhances succinate dehydrogenase activity in L6 myoblasts.
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    ABSTRACT: Contraction of skeletal muscle generates pressure stimuli to intramuscular tissues. However, the effects of pressure stimuli, other than those created by electricity or nerve impulse, on physiological and biochemical responses in skeletal muscles are unknown. The purpose of this study is to examine the effects of a pure pressure stimulus on metabolic responses in a skeletal muscle cell line. Atmospheric pressure was applied to L6 myoblasts using an original apparatus. Succinate dehydrogenase (SDH) activity was evaluated by colorimetric assay using tetrazolium monosodium salt. The amounts of 2-deoxy-[(3)H]glucose uptake and lactate release were measured. SDH activity was 2.6- to 2.9-fold higher in pressurized L6 cells than in nonpressurized L6 cells (P < 0.01), and 2-deoxy-[(3)H]glucose uptake was 2.2-fold higher (P < 0.001). In addition, the amount of released lactate decreased from 6.8 to 3.7 mumol/dish when pressure was applied (P < 0.001). In contrast, the intracellular lactate contents of the pressurized cells were higher than those of nonpressurized cells (P < 0.01). However, the total amount of released lactate and intracellular lactate was lower in the pressurized cells than in nonpressurized cells. These findings demonstrate that a pure pressure stimulus enhances aerobic metabolism in L6 skeletal muscle cells and raise the possibility that elevated intramuscular pressure during muscle activity may be an important factor in stimulating oxidative metabolic responses in skeletal muscles.
    AJP Endocrinology and Metabolism 01/2005; 287(6):E1064-9. · 4.75 Impact Factor
  • Article: A woman with infectious endocarditis caused by Abiotrophia defectiva.
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    ABSTRACT: A 74-year-old woman with recurrent fever and multiple joint pain was admitted to Hokkaido University Hospital. Trans-esophageal echocardiogram revealed bacterial vegetation and destruction of the aortic valve. Although few bacteria grew in regular blood agar, Gram-positive coccobacillus was specifically grown in chocolate blood agar and Brucella agar, and it was identified to be Abiotrophia defectiva. Infectious endocarditis caused by Abiotrophia defectiva was diagnosed, she was treated with diuretics, penicillin G and gentamicin, and she immediately improved. Infectious diseases caused by Abiotrophia defectiva are extremely rare, and identification of this pathogen is important, as its bacterial characteristics require proper attention.
    Internal Medicine 11/2004; 43(10):1000-4. · 0.94 Impact Factor
  • Article: Positional ventricular tachycardia.
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    ABSTRACT: A 60-year-old man showed nonsustained repetitive monomorphic VT in the left lateral position, but this was terminated by deep inspiration. Echocardiography and MRI demonstrated a false tendon extending from the apex to the basal septum where the VT could have originated. Spontaneous remission occurred during the 16-year follow-up.
    Pacing and Clinical Electrophysiology 11/2004; 27(10):1437-9. · 1.35 Impact Factor
  • Article: Can exercise training with weight loss lower serum C-reactive protein levels?
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    ABSTRACT: C-reactive protein (CRP), an obesity-related inflammatory marker, is a promising predictor for cardiovascular disease and may be a mediator for atherogenesis. It has been reported that diet-induced weight loss lowered CRP levels. However, the effect of exercise training, another therapy that can reduce weight, on CRP is still unclear. We examined effects of exercise training with weight loss on CRP levels and conventional cardiovascular risks. A total of 227 apparently healthy women were recruited, and 199 subjects (average age 52 years) completed a 2-month weight reduction program consisting of supervised aerobic exercises. After the program, weight was reduced from 65.8 to 62.8 kg (P<0.0001), and all conventional variables were remarkably improved. Similarly, CRP levels were significantly decreased, from 0.63 (0.28 to 1.19) to 0.41 (0.18 to 0.80) mg/L (P<0.0001). However, in contrast to other variables, the changes in CRP levels were not proportionally associated with the extent of weight reduction. In the quartile analysis of % weight reduction, the largest weight reduction quartile did not show significant decreases in CRP levels, whereas moderate quartile showed remarkable CRP decreases. Exercise training with weight reduction disproportionately lowered CRP levels. Considering inflammatory status, there might be an optimal pace of exercise with weight loss.
    Arteriosclerosis Thrombosis and Vascular Biology 10/2004; 24(10):1868-73. · 6.37 Impact Factor
  • Article: Comparisons of the skeletal muscle metabolic abnormalities in the arm and leg muscles of patients with chronic heart failure.
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    ABSTRACT: It has been suspected for some time that patients with chronic heart failure (CHF) have abnormal muscle metabolism, so in the present study the muscle metabolism of the arm and leg were compared by (31)P magnetic resonance spectroscopy ((31)P-MRS) to examine the relationship to exercise tolerance. The study group comprised 13 patients and 11 normal controls. Calf-plantar and forearm-wrist flexion were performed to evaluate the metabolic capacity assessed as the phosphocreatine breakdown rate (PCr-slope) and muscle pH at a submaximal (70% peak) work rate (submax-pH). Exercise of both the arm and leg resulted in an earlier decrease in PCr and muscle pH in patients with CHF compared with controls. There were significant correlations between peak oxygen uptake (peak V(O2)) and the PCr-slope in both limbs in patients with CHF (forearm: r=0.63, p<0.05; calf: r=0.60, p<0.05), but no correlations in normal controls. There was a close correlation between the ventilatory anaerobic threshold (AT) and the PCr-slope in the calf (r=0.85, p<0.01), but not in the forearm in patients with CHF. Submax-pH in both upper and lower limbs was not significantly correlated to peak V(O2) or AT in either patients with CHF or controls. Although metabolic abnormalities during exercise are seen in both arms and legs, leg muscle abnormalities, in particular, are closely related to systemic exercise intolerance in patients with CHF.
    Circulation Journal 06/2004; 68(6):573-9. · 3.77 Impact Factor
  • Article: Pure pressure stress increased monocarboxylate transporter in human aortic smooth muscle cell membrane.
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    ABSTRACT: Lactate is formed and utilized continuously under fully aerobic conditions. Lactate is oxidized actively at all times, especially during exercise. Family of monocarboxylate transport proteins (MCTs) that are differentially expressed in cells and tissues accomplishes the facilitated transport of lactate across membranes. Previously we reported that there is MCT1 in blood circulation. We also reported the pressure stress stimulated cell proliferation in aortic smooth muscle cells (HASMC). In this experiment we attempted to prove the existence of MCT1 in HASMC and to clarify the effect of pressure stress on MCT1 localization in HASMC. We determined succinate dehydrogenase (SDH) activity as a marker of energy metabolism in cells. SDH activity was increased by pressure stress. Lactate enhanced the SDH activity under pressure stress (160 mmHg for 3 h) as dose dependent manner. On the other hand, lactate excretion was suppressed by the addition of lactate. We could detect MCT1 in the cytosolic and the membrane fractions of HASMC. The pressure stress increased MCT1 in the membrane fraction in the presence of extracellular lactate. In summary, we proved the existence of MCT1 in HASMC. Pressure stress changed the localization of MCT1. The increased membranous MCT1 may transport lactate for energy metabolism in cells.
    Molecular and Cellular Biochemistry 05/2004; 259(1-2):151-6. · 2.06 Impact Factor
  • Article: Percutaneous coronary intervention for central sleep apnoea with ischaemic cardiomyopathy.
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    ABSTRACT: Central sleep apnoea is often recognized in patients with heart failure. Although the medical treatment to improve cardiac function is effective for sleep apnoea, direct evidence that improved cardiac function ameliorates sleep apnoea has not been reported due to the fact that a particular drug may affect a multitude of organs. We present a chronic heart failure patient with central sleep apnoea whose nocturnal desaturation was improved by percutaneous coronary intervention that resulted in improved cardiac function. This is the first case where percutaneous coronary intervention improved sleep apnoea, suggesting that the improved cardiac function led to amelioration of sleep apnoea.
    Acta cardiologica 03/2004; 59(1):63-5. · 0.61 Impact Factor
  • Article: A 44-kDa of protein identical to the N-terminal amino acid sequence of MCT1 in human circulation.
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    ABSTRACT: A family of specific carrier protein designated as monocarboxylate transporter (MCT) has been known to transport the lactate and other moncarboxylates in mammalian cells. We hypothesized the presence of serum protein in human circulation that may works as a lactate carrier and that biochemical structure would possesses common structure with MCT on the plasma membrane. Immunoblot analysis with an anti-MCT1 polyclonal antibody suggested the presence of a 44-kDa protein in human circulation and N-terminal amino acid sequencing exhibited a stretch of 14 amino acids which is completely identical to MCT1. The unbound fractions from the GST-MCTI fusion protein-immobilized glutathione sepharose 4B column demonstrated that lactic acid concentration began to increase with one fraction delay compared to Sepharose 4B and GST-immobilized column. When lactic acid was washed away with PBS, lactic acid concentrations in the effuluent constantly decreased in both Sepharose 4B and GST-immobilized column. However, GST-MCT1-immobilized column showed specific convex curve from fraction approximately 3 mM of lactate and demonstrated wash out delay compared to Sepharose 4B and GST-immobilized column. These observations demonstrated biochemical and immunological similarities between a 44-kDa protein purified from human serum and MCT1 present on the plasma membrane. The studies on MCT1-fusion protein suggested possible functional properties of a 44-kDa protein as a lactate buffer by holding and unhand a lactate according to the lactate concentration in human blood. The experiments described herein have suggested the existence of lactate carrier in human circulation which is free from plasma membrane.
    Molecular and Cellular Biochemistry 07/2003; 248(1-2):217-23. · 2.06 Impact Factor
  • Article: Images in cardiovascular medicine. Left ventricular asynchrony caused by an intramuscular lipoma: computed tomographic and magnetic resonance detection.
    Circulation 07/2003; 107(21):e200-1. · 14.74 Impact Factor