Mataichi Okubo

The chromatin-remodeling complex WINAC targets a nuclear receptor to promoters and is impaired in Williams syndrome

S phase progression. WINAC mediates the recruitment Hirochika Kitagawa,1,2 Ryoji Fujiki,1 Kimihiro Yoshimura,1 Yoshihiro Mezaki,1 Yoshikatsu Uematsu,1 Daisuke Matsui,1 Satoko Ogawa,1 Kiyoe Unno,1,3 Mataichi Okubo,3 Akifumi Tokita,3 Takeya Nakagawa,4 Takashi Ito,4 Yukio Ishimi,5 of unliganded VDR to VDR target sites in promoters, Hiromichi Nagasawa,6 Toshio Matsumoto,2 while subsequent binding of coregulators requires liJunn Yanagisawa,1,7 and Shigeaki Kato1,7,* gand binding. This recruitment order exemplifies that Institute of Molecular and Cellular Biosciences an interaction of a sequence-specific regulator with a University of Tokyo chromatin-remodeling complex can organize nucleo1-1-1 Yayoi somal arrays at specific local sites in order to make Bunkyo-ku promoters accessible for coregulators. Furthermore, Tokyo 113-0032 overexpression of WSTF could restore the impaired Japan recruitment of VDR to vitamin D regulated promoters 2 First Department of Internal Medicine in fibroblasts from Williams syndrome patients. This University of Tokushima School of Medicine suggests that WINAC dysfunction contributes to 3-18-15 Kuramoto-cho Williams syndrome, which could therefore be considTokushima 770-8503 ered, at least in part, a chromatin-remodeling factor Japan disease. 3 Department of Pediatrics

Apoptosis as a Possible Cause of Wall Thinning in End-Stage Hypertrophic Cardiomyopathy

A 15-year-old boy with hypertrophic cardiomyopathy died of congestive heart failure with progressive left ventricular wall thinning with poor systolic function. Microscopic examination revealed patchy fibrosis in the ventricular myocardium with wall thinning, and immunohistochemical evaluation of apoptosis showed apoptotic cells and bodies in the destroyed myocytes along the border between the fibrotic area and myofibril.

Age Dependency of Stiffness of the Abdominal Aorta and the Mechanical Properties of the Aorta in Kawasaki Disease in Children

Abstract. Measuring aortic distensibility has been shown to be useful in adults as a noninvasive method in the early detection of atherosclerosis. This study had two purposes: to assess the stiffness of the abdominal aorta by using two-dimensional echocardiography (2DE) in healthy neonates, children, and adults and to assess aortic distensibility in children with Kawasaki disease in acute and subacute phases. The study comprised 168 healthy subjects and 40 patients with Kawasaki disease. We recorded systolic (Ps) and diastolic (Pd) blood pressure and measured aortic diameter (Dd) at both minimum diastolic pressure and maximum systolic expansion (Ds) by 2DE. These measurements were used to determine (1) aortic strain (S) = (Ds−Dd)/Dd, (2) pressure strain elastic modulus (Ep) = (Ps−Pd)/S, and (3) normalized Ep (Ep*) =Ep/Pd. Significant correlations were found between S and age, Ep and age, and Ep* and age. In Kawasaki disease, Ep and Ep* showed negative correlations to day after onset. The aorta was less distensible in infants, became soft in 12- to 16-year-olds, and then stiffened with increasing age among normal subjects. In Kawasaki disease, aortic stiffness was high at the acute phase and normal at the subacute phase. These tendencies may be related to the biological characteristics of smooth muscle cells.

Dilatation Mechanism of Balloon Angioplasty in Children: Assessment by Angiography and Intravascular Ultrasound

AbstractPurpose: 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 (Χ2= 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.

Late persistent expressions of ICAM-1 and VCAM-1 on myocardial tissue in children with lymphocytic myocarditis.

BACKGROUND Both intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) have been implicated in cardiac allograft rejection. However, there is little information about the relationship between the expression of these adhesion molecules and myocarditis in children. METHODS AND RESULTS Immunoreactivities of ICAM-1 and VCAM-1 were examined by enzyme immunoassay in 31 biopsy specimens obtained from 11 pediatric patients with biopsy-proven myocarditis or cardiomyopathy. Five of the 11 patients had clear evidence of acute myocarditis. The other 6 had ECG abnormalities identified by mass screening for heart disease, and subsequently had been histologically diagnosed as having non-specific cardiomyopathy. The period between onset of myocarditis or identification of ECG abnormality and immunohistochemical studies was 23 to 60 days and 8 months to 3 years, respectively. Expression of ICAM-1 and VCAM-1 was assessed by counting ICAM-1 and VCAM-1 positive vessels and dividing by the total number of vessels. ICAM-1 was significantly present on 81% (P < 0.01) of myocardial tissue samples in the 5 patients with healing-stage acute myocarditis, and on 45% (P < 0.05) in the remaining 6 patients with non-specific cardiomyopathy, compared with 24% in control specimens obtained from right ventricular muscle resected at surgery for tetralogy of Fallot. VCAM-1 was also present on 50% (P < 0.05) of the samples from the 5 patients with acute myocarditis, but was not present in those with non-specific cardiomyopathy. CONCLUSION This persistent expression of ICAM-1 suggests that myocardial cell damage may persist immunologically for a long period in myocarditis. In addition, immunostaining for these adhesion molecules may be diagnostic value in clinically silent lymphocytic myocarditis and chronic cardiomyopathy.

Corticosteroid therapy for ventricular tachycardia in children with silent lymphocytic myocarditis

OBJECTIVE The objective of our study was to describe the efficacy of corticosteroids for ventricular tachycardia in four children with structurally normal hearts in whom endomyocardial biopsy revealed histologic changes of lymphocytic myocarditis. PATIENTS The four patients had unexplained ventricular tachycardia. Three dysrhythmias were sustained, and one was inducible by exercise. Patient ages ranged from 4 months to 12 years. Three of the four patients had no symptoms. In two of them, ventricular tachycardia was identified by mass screening for heart disease. Two patients received oral steroids and two received pulse steroid therapy. RESULTS In all four patients, significant underlying diseases were not found by noninvasive evaluation. Right ventricular endomyocardial biopsy revealed abnormal histologic findings of chronic lymphocytic myocarditis in all patients. Steroid therapy was effective in all four patients, two of whom received methylprednisolone pulse therapy. CONCLUSIONS We conclude that unexplained ventricular tachycardia may be the only manifestation of clinically silent myocarditis. Steroid therapy should therefore be considered if conventional antiarrhythmic medication is not effective and histologic findings confirm the presence of lymphocytic myocarditis.

Mechanism of balloon angioplasty in children with arterial stenosis assessed by intravascular ultrasound and angiography

Fifteen patients were examined before and immediately after balloon angioplasty with a 4.3F, 30 MHz rotational tip intravascular ultrasound system. In 12 (80%) patients, 13 procedures could be analyzed because of sufficient image quality. The lesions for intravascular ultrasound (IVUS) study consisted of pulmonary arterial stenosis in 4 patients, Blalock-Taussig shunt stenosis in 3, coarctation of the aorta in 2, subclavian artery stenosis in 1, renal artery stenosis in 1, and ductus arteriosus in 1. Three distinctive morphologic types were identified: Group I had arterial stretching (3 patients); group IIa had superficial tearing (3); group IIb had deep intimal-medial tearing (5); group III had dissection (2). In the narrowest site, minimal and maximal luminal diameters, luminal area before and after balloon angioplasty were 3.5 +/- 1.8 mm vs 4.5 +/- 2.5 mm, 4.1 +/- 2.1 mm vs 5.4 +/- 3.5 mm, and 49.8 +/- 30.2 mm vs 88.3 +/- 45.2 mm2, respectively. The recoil value of group IIb with appropriate balloon angioplasty was approximately 0.3. IVUS may be an useful modality for evaluating the morphologic mechanism of dilatation after balloon angioplasty.

Spring coil retraction in coil occlusion of persistent ductus arteriosus

Aims To present the short and intermediate term results of coil occlusion of persistent ductus arteriosus and the results of radiographic measurements of spring coils implanted to treat patent ducts. Patients 22 children underwent coil occlusion. Their ages ranged from 2 years 9 months to 12 years 10 months (mean (SD) age, 6.5 (3.6) years). The duct diameter ranged from 1.0 to 3.5 mm at the narrowest point (mean 2.6 (0.7) mm). In 11 of the children regular coils were implanted using the non-attached system, while in the other 11 the detachable coil embolisation system was used. Results 12 children (55%) had no significant residual leaks immediately after procedures involving a single coil delivery. The remaining 10 (45%) had residual leaks immediately after the procedure, although no patient with a large duct showed residual leakage 18 months after the procedure. Radiographic measurement of the coils showed that all implanted coils retracted to 65–85% of their original size immediately after occlusion. This retraction was more evident in patients showing spontaneous closure of the residual shunt or having a coil 8 mm in diameter. Conclusions Coil embolisation is an acceptable method for occluding persistent ductus arteriosus. Retraction of implanted coils is common in the follow up period. Such retraction may be related to spontaneous closure of residual shunt after embolisation.

Recanalisation after coil embolisation of persistent ductus arteriosus

A 5 year old girl underwent recanalisation after coil embolisation of a persistent ductus arteriosus. Recanalisation is uncommon after coil embolisation and may be related to shrinkage of the coil, a change in its position, and ductal shape.

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 Tokyos 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.