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Dive into the research topics where Kenya Nishioka is active.

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Featured researches published by Kenya Nishioka.


Circulation | 1991

Plasma endothelin concentrations in patients with pulmonary hypertension associated with congenital heart defects. Evidence for increased production of endothelin in pulmonary circulation.

Muneo Yoshibayashi; Kenya Nishioka; Kazuyasu Nakao; Yoshihiko Saito; Masahiko Matsumura; Tadashi Ueda; Shinji Temma; Gotaro Shirakami; Hiroo Imura; Haruki Mikawa

BackgroundTo elucidate the pathophysiological significance of endothelin in pulmonary hypertension associated with congenital heart defects, we measured plasma endothelin-like immunoreactivity (ET-LI) concentrations by using radioimmunoassay in 18 patients with pulmonary hypertension (PH group; age, 6 months to 12 years) in comparison with 27 patients without pulmonary hypertension (non-PH group; age, 6 months to 12 years). Methods and ResultsBlood samples were obtained from the vena cava, right atrium, right ventricle, left or right pulmonary artery, and pulmonary vein or the pulmonary arterial wedge position (pulmonary venous blood) during cardiac catheterization. Plasma ET-LI concentrations in the PH group were significantly higher than those in the non-PH group at all sampling sites. In the PH group, plasma ET-LI concentration showed a significant increase between the right ventricle and pulmonary artery and between the pulmonary artery and pulmonary vein. The increment of plasma ET-LI concentrations from the right ventricle to the pulmonary vein was significantly larger in the PH group than in the non-PH group and was significantly correlated with pulmonary artery pressure. ConclusionsPlasma ET-LI concentrations were elevated in patients with pulmonary hypertension; the elevation was due to the increased production of ET-LI in pulmonary circulation, indicating the possible involvement of endothelin in the pathophysiology of pulmonary hypertension.


American Journal of Cardiology | 1980

Clinicopathologic study of abnormal Q waves in Kawasaki disease (mucocutaneous lymph node syndrome): An infantile cardiac disease with myocarditis and myocardial infarction☆

Hisayoshi Fujiwara; Cheng-Hsiung Chen; Takako Fujiwara; Kenya Nishioka; Chuichi Kawai; Yoshihiro Hamashima

Abstract A correlative study of abnormal Q waves and pathologic findings was performed on 15 hearts from children with Kawasaki disease. Gross pathologic study revealed acute angiitis with pericarditis, acute myocarditis and coronary heart disease as the result of angiitis. Three hearts in infants with abnormal Q waves in leads I and aVL and chest leads had gross transmural fibrosis in the anteroseptal-lateral walls of the left ventricle. Coagulation necrosis (acute myocardial infarction) or fibrosis, or both, in more than 30 percent of the wall thickness in the posterior ventricular wall was found in four of five hearts in infants with abnormal Q waves in leads II, III and aVF. Seven of the 15 infants had no abnormal Q waves, and only 2 of the 7 had myocardial damage in over 30 percent of the wall thickness. In 9 of the 15 hearts there were 11 gross areas of fibrosis; in these hearts there was a corresponding severe stenosis of more than 90 percent due to organization in the major coronary arteries supplying these areas. In three hearts with coagulation necrosis, the coronary occlusion was caused by fresh large thrombi. In the six hearts without sizable fibrosis, the grade of stenosis due to organization was less than 75 percent in each of the major coronary arteries. Coronary aneurysm due to angiitis was seen in 12 of the 15 hearts, and at autopsy fresh large thrombi were seen in each aneurysm. Ten of the 12 hearts exhibited sizable areas of myocardial damage. Three hearts without aneurysm manifested angiitis with mild stenosis of less than 25 percent, but there were no macroscopic fresh thrombi in any of the major coronary arteries. Thus, abnormal Q waves in children with Kawasaki disease almost always reflect myocardial damage in over 30 percent of the wall thickness of the left ventricle. Electrocardiograms are useful to determine the anterior or posterior localization of the damage. Nevertheless, the possibility of transmural and nontransmural areas of damage cannot be excluded in the absence of abnormal Q waves.


The Journal of Pediatrics | 1987

Relationship between plasma atrial natriuretic polypeptide concentration and hemodynamic measurements in children with congenital heart diseases

Kiyoshi Kikuchi; Kenya Nishioka; Tadashi Ueda; Michiko Shiomi; Yoshiaki Takahashi; Akira Sugawara; Kazuwa Nakao; Hiroo Imura; Chuzo Mori; Haruki Mikawa

The plasma alpha-atrial natriuretic polypeptide (alpha-ANP) concentration in the peripheral veins of children with congenital heart diseases was measured by radioimmunoassay and compared with cardiac catheterization data. Every patient with heart failure had a higher alpha-ANP concentration (132.1 to 858.7 pg/mL) than the upper limit of the normal range (11.7 to 98.7 pg/mL), whereas more than half of the patients without heart failure had a normal alpha-ANP concentration. Although none of the 13 children with atrial septal defect had heart failure, their mean (+/- SD) plasma alpha-ANP concentration (99.4 +/- 40.7 pg/mL) was significantly higher than that in control children (44.6 +/- 22.3 pg/mL). The plasma alpha-ANP concentration was significantly correlated with the pulmonary blood flow/systemic blood flow (Qp/Qs) ratio in the children with atrial septal defect. In the 34 children with ventricular septal defect the plasma alpha-ANP concentration increased in relation to increasing size of the defect. The plasma alpha-ANP concentration was significantly correlated with the Qp/Qs ratio, pulmonary artery pressure, and left atrial pressure, estimated from mean pulmonary artery wedge pressure, in the children with ventricular septal defect. In the children with tetralogy of Fallot, the mean plasma alpha-ANP concentration was normal, and mean right and left atrial pressures were not increased. The elevated alpha-ANP concentration in the three patients with heart failure decreased after their conditions improved with various treatments. Thus the measurement of alpha-ANP concentration may be valuable in evaluating the presence or absence of heart failure and the response to treatment in children with congenital heart diseases. Distention of the right and left atrial might induce the release of alpha-ANP in patients with atrial and ventricular septal defects, respectively.


Journal of Cardiovascular Pharmacology | 1991

Plasma endothelin levels in healthy children: high values in early infancy.

Muneo Yoshibayashi; Kenya Nishioka; Kazuwa Nakao; Yoshihiko Saito; Shinji Temma; Masahiko Matsumura; Tadashi Ueda; Gotaro Shirakami; Hiroo Imura; Haruki Mikawa

We measured plasma endothelin-1-like immunoreactivity (ET-1-LI) levels in the peripheral vein of 70 healthy children (37 males and 33 females) aged 5 days to 15 years to establish the normal range in children, and compared them with those in 11 normal adults (age, mean +/- SD; 29.5 +/- 5.7 years, 6 males and 5 females). Plasma ET-1-LI levels (pg/ml, mean +/- SD) in children of each age group and adults were as follows: children younger than 1 month = 23.4 +/- 3.9 (n = 10), 1-3 months = 25.0 +/- 6.1 (n = 8), 3-6 months = 17.0 +/- 1.4 (n = 8), 6 months to 1 year = 14.0 +/- 1.7 (n = 13), 1-5 years = 13.8 +/- 2.6 (n = 11), 5-10 years = 13.6 +/- 1.6 (n = 10), 10-15 years = 12.9 +/- 2.2 (n = 10), and adults = 13.2 +/- 2.4 (n = 11). There was no significant difference in plasma ET-1-LI levels between males and females in each age group. Plasma ET-1-LI levels in children younger than 3 months were significantly (p less than 0.01) higher than those in older children or adults. After 3 months of age, plasma ET-1-LI levels were nearly constant at all ages. This is the first report to establish the normal range of plasma ET-1-LI levels in children.


American Journal of Cardiology | 1986

Comparison of macroscopic, postmortem, angiographic and two-dimensional echocardiographic findings of coronary aneurysms in children with Kawasaki disease

Takako Fujiwara; Hisayoshi Fujiwara; Tadashi Ueda; Kenya Nishioka; Yoshihiro Hamashima

To assess why the results of 2-dimensional echocardiography (2-D echo) for diagnosis of coronary aneurysm in patients with Kawasaki disease differed from those of cineangiography, the macroscopic, postmortem, angiographic and 2-D echocardiographic findings of 8 autopsied hearts of infants and children with Kawasaki disease were compared. Postmortem angiography and 2-D echo yielded similar results in aneurysms in which there was no thrombus, organization or marked thickening of the arterial wall. However, in aneurysms with complete or incomplete occlusion of the dilated cavity due to thrombi, organization or marked thickening of arterial wall, angiographic results reflected only the free cavity of the coronary aneurysm, but could not detect the original aneurysm. Two-dimensional echocardiography disclosed an echo-free space representing the original aneurysm, in which some materials, suggesting thrombi or organization, were found. However, it did not reveal whether the aneurysm was occlusive. This finding indicates that the discrepancies between the results of cineangiography and 2-D echo are attributable to the formation of large thrombi, organization or marked thickening of the arterial wall in the aneurysmal cavity. It is clinically important to know these limitations of angiography and 2-D echo.


American Journal of Cardiology | 1981

Left ventricular volume characteristics in children with tricuspid atresia before and after surgery

Kenya Nishioka; Tetsuro Kamiya; Tadashi Ueda; Tadashi Hayashidera; Chuzo Mori; Yutaka Konishi; Norikazu Tatsuta; Jay M. Jarmakani

Abstract Left ventricular volume variables (left ventricular end-diastolic volume, ejection fraction, mass and systolic output) were quantified in (1) 13 patients with tricuspid atresia preoperatively (type Ia, 3 patients; type Ib, 9 patients; type IIb, 1 patient), (2) 4 patients after a shunt procedure (Blalock-Taussig, 3; Glenn, 1), and (3) 1 patient after corrective surgery. Cardiac catheterization and angiography were performed at age 1 month to 5.8 years (mean 1.4 years). All patients had decreased pulmonary blood flow. The results were compared with data in 15 patients with no significant heart disease. Left ventricular end-diastolic volume was significantly greater than normal in 12 of the 13 patients. Left ventricular mass was significantly greater than normal, but ejection fraction was significantly less than normal. There was a positive correlation between ejection fraction and systemic oxygen saturation. Left ventricular systolic index was normal in 9 of the 13 patients preoperatively. After a shunt procedure, left ventricular end-diastolic volume and systolic index increased significantly in all four patients, and ejection fraction improved greatly in three of the four. After corrective surgery, left ventricular end-diastolic volume and left ventricular systolic index returned to the normal range and left ventricular ejection fraction improved. These findings suggest that patients with tricuspid atresia have impaired left ventricular function.


Pediatric Cardiology | 1986

Aortopulmonary window, aortic origin of the right pulmonary artery, and interrupted aortic arch: Detection by two-dimensional and color Doppler echocardiography in an infant

Doris A. Mendoza; Tadashi Ueda; Kenya Nishioka; Yoshihumi Yokota; Haruki Mikawa; Shinichi Nomoto; Ario Yamazato; Fukumasu H; Toshihiko Ban

Aortopulmonary (AP) window [6, 10] aortic origin of the right pulmonary artery (RPA) [10], and interruption of the aortic arch [3) are each uncommon malformations . Their coexistence provides a complex that is a rare diagnostic challenge . We here report on an infant who had a combination of all these cardiovascular defects, presenting With cyanosis and congestive heart failure . The use of two-dimensional echocardiography (2DE) in the detection of AP window has been previously described (5, 9, 11] as has been that of anomalous origin of the RPA from the ascending aorta [4, 5, 11]. In our case 2DE detected both the AP window and the aortic origin of the RPA . We also describe the clinical value of the new two-dimensional color Doppler echocardiography (2D color Doppler), as developed by Omoto and associates [7], for the noninvasive visualization of shunting across the aortopulmonary window, in lieu of cineangiography .


European Journal of Endocrinology | 1995

Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth

Muneo Yoshibayashi; Tetsuro Kamiya; Yoshihiko Saito; Kazuwa Nakao; Kenya Nishioka; Shinji Temma; Hiroaki Itoh; Gotaro Shirakami; Hisayuki Matsuo


Journal of Molecular and Cellular Cardiology | 1994

Age-related Acute Adriamycin Cardiotoxicity in Mice

Masahiko Matsumura; Kenya Nishioka; Tatsuya Fujii; Muneo Yoshibayashi; Kouji Nozaki; Youhei Nakata; Shinji Temma; Tadashi Ueda; Haruki Mikawa


Japanese Circulation Journal-english Edition | 1978

MITRAL INSUFFICIENCY SECONDARY TO MUCOCUTANEOUS LYMPH NODE SYNDROME A CASE REPORT OF SUCCESSFUL SURGICAL TREATMENT

Yutaka Konishi; Norikazu Tatsuta; Shigehito Miki; Yukio Chiba; CHlN-TZER Kao; Yorinori Hikasa; Michio Yokota; Kenya Nishioka; Tadashi Ueda; Tetsuro Kamiya; Takehiro Sugiyama

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Tadashi Ueda

Kanazawa Medical University

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