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.

Acute Disease↗

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

Toxicological and immunological evaluation of the immunosuppressant 15-deoxyspergualin in BALB/c mice: an in vivo and in vitro study.

The toxicological aspects as well as the immunosuppressive mechanism of 15-deoxyspergualin (DSP) were studied using BALB/c mice. Five-week-old animals were subcutaneously given phosphate-buffered saline (PBS; Group 1) or DSP at 0.5 (Group 2) to 5.0 mg (Group 4) per kg body weight daily for 1 to 3 months. They were sacrificed to obtain blood for hematology and liver function studies. The spleen, taken simultaneously, was histologically examined, the T cell surface markers of splenocytes were flow cytometrically measured, and their interleukin 2 (IL-2) production induced in vitro by Enterotoxin A (Ent A) was assayed using CTLL cells. Additionally, the in vitro effect of DSP on IL-2 generation and plaque forming cell (PFC) production was studied using splenocytes of non-treated mice. During the 3 months of treatment, the body weight slowly increased in Groups 1 and 2, while the body weight of the 2.5-mg DSP mouse group (Group 3) was significantly lower on days 28 and 56 of treatment compared with Group 1 of the same age (P less than 0.05). The administration of DSP at 5.0 mg/kg (Group 4) caused marked reduction in body weight of the animals. They were sacrificed on day 28 because of their worsening general condition. WBC and RBC counts decreased in Group 3 on days 57 and 93, and the platelet number increased on day 57. A liver function test was not affected by DSP treatment except for an elevated SGOT in Group 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗