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K Yabuta

Publications and source records attributed to K Yabuta.

172 records · Page 10Linked to original sources
PubMedDate not supplied

Clinicopathologic characteristics of hypertrophic cardiomyopathy detected during mass screening for heart disease.

Between 1981 and 1992 a total of 10 patients with hypertrophic cardiomyopathy (HCM) were detected by mass screening for heart disease in Tokyo's Adachi Ward. Four were first grade elementary school children and six were first grade junior high school adolescents. Two-dimensional echocardiography at the initial evaluation revealed asymmetric septal hypertrophy in four patients, diffuse hypertrophy of the left ventricle in five, and poor left ventricular contractility with wall thinning in one (dilated phase). Three of the five patients with diffuse hypertrophy progressed to asymmetric septal hypertrophy during the average 4-year follow-up period. The degree of septal thickness and the left ventricular wall thickness index were significantly less than in those of young adult controls (12 +/- 3 versus 21 +/- 9 mm, p < 0.05; and 22 +/- 4 versus 28 +/- 16 mm, p < 0.05, respectively). Right ventricular endomyocardial biopsy specimens obtained from 9 of the 10 patients showed features typical of HCM (e.g., myocyte hypertrophy with myofibril disarray) in five patients and atypical features (mainly interstitial fibrosis with perivascular cell infiltration) in another four. One patient with dilated phase disease died of congestive heart failure 6 months after the initial evaluation. These results indicate that HCM detected during mass screening is a mild form of the disease and may have atypical pathologic features, such as interstitial fibrosis and perivascular cell infiltration, mimicking the sequela of chronic myocarditis.

Adolescent↗
PubMedDate not supplied

Dilatation mechanism of balloon angioplasty in children: assessment by angiography and intravascular ultrasound.

PURPOSE: Little information is available about the dilatation mechanism in children. This prospective study aimed to (1) evaluate the dilatation mechanism of balloon angioplasty in children with arterial stenosis, and (2) compare the morphological changes seen by intravascular ultrasound (IVUS) and angiography. METHODS: Twenty consecutive patients, who had undergone a total of 23 procedures, were examined before and immediately after balloon angioplasty with a 4.3 Fr, 30 MHz rotational tip IVUS system. The lesions for IVUS study had resulted from coarctation of the aorta in six patients, pulmonary arterial stenosis in five, Blalock-Taussig shunt stenosis in three, subclavian artery stenosis in two, renal artery stenosis in two, coronary artery stenosis in one and ductus arteriosus in one. RESULTS: Four distinctive morphological types were identified: type I with arterial stretching, type IIa with superficial tearing, type IIb with deep intimal-medial tearing, type III with flap formation, and type IV with dissection. The diameter of the narrowest site before and after balloon angioplasty increased significantly from 2. 1 +/- 1.4 mm to 4.6 +/- 3.4 mm (p < 0.001). Eighteen of the 23 angioplasty procedures (78%) were considered to be successful, with a dilatation ratio of more than 50%. In most patients with successful dilatation, non-stretch mechanisms such as tearing, flap formation, or dissection were found. The positive percent (70%) of non-stretch mechanisms seen by IVUS was significantly higher than the positive findings (39%) by angiography (Chi2 = 6.47, p < 0.02). CONCLUSIONS: Non-stretch morphology of the arterial wall may be a common mechanism of dilatation after balloon angioplasty in children with arterial stenosis. IVUS is a useful modality for evaluating the effectiveness of balloon angioplasty and the mechanism of dilatation in individual cases.

Adolescent↗
PubMedDate not supplied

Vitamin D metabolism in pre-operative extrahepatic biliary atresia.

In order to clarify the pathogenesis of rickets in preoperative patients with extrahepatic biliary atresia, we evaluated baseline serum 25-OHD and 1,25(OH)2D levels and correlated serum 25-OHD levels with increase in age and season of birth in 16 preoperative patients. Further, parenteral vitamin D2 tolerance tests were performed in 5 cases. Serum 25-OHD and 1,25(OH)2D levels were significantly lower than those in 15 normal controls. There was a negative correlation between the serum 25-OHD levels and increase in age. The patients born during the winter had lower serum 25-OHD concentrations than those born in summer. The mean value of increased 25-OHD levels after the parenteral vitamin D2 tolerance tests did not differ from that of 6 controls. Since there was no impairment of vitamin D 25-hydroxylation, the reduction in serum 25-OHD may therefore be mainly due to disturbed intestinal vitamin D absorption. It was also concluded that season of birth and increase in age are pathogenic factors in the etiology of rickets in preoperative patients with extrahepatic biliary atresia.

Biliary Atresia↗