Makoto Nakazawa

Programmed Cell Death in the Myocardium of Arrhythmogenic Right Ventricular Cardiomyopathy in Children and Adults

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibrofatty replacement of the right ventricular myocardium. Recently, the myocardial loss in ARVC has been suggested to be related to apoptosis. However, it is still unknown whether this phenomenon is already established in the myocardium of pediatric cases with this disease. We examined the histopathologic characteristics of the ventricular myocardium in specimens obtained from 10 patients, including 3 children with ARVC, and investigated the occurrence of apoptosis in the myocardium by terminal deoxyribonucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay and agarose-gel electrophoresis of DNA. Endomyocardial biopsy specimens from the 10 cases and a necropsy sample from one adult case with ARVC were examined. Histopathologic examination of biopsy specimens from the pediatric cases revealed extensive fibrosis. Typical fatty infiltration was demonstrated in one of the 3 pediatric cases. These findings were similar to those in adult cases; the histopathologic index based on the severity of myocardial damage, including myocyte degeneration and fibrosis, was not significantly different from that in adult cases. TUNEL assay revealed positive reactivity of the myocardial cells. The apoptotic index was 1.4 +/- 0.4% in children and 1.6 +/- 0.5% in adults (difference not statistically significant). Agarose-gel electrophoresis of a DNA extract of the myocardial tissue of the autopsy case revealed DNA fragmentation. Cases with idiopathic ventricular tachycardia and control cases with a cardiac transplant (with no rejection) had minimal histopathologic findings and negative reactivity in the TUNEL assay. These results indicate that myocardial damage is already established in cases diagnosed as ARVC in childhood, and suggest that the myocardial damage is closely related to apoptosis in children, as well as in adults, in this disease.

Intraluminal appendiceal fluid is a predictive factor for recurrent appendicitis after initial successful non-operative management of uncomplicated appendicitis in pediatric patients

BACKGROUND The risk factors for recurrent appendicitis in pediatric patients are unclear. This study aimed to identify the predictive factors for recurrent appendicitis in pediatric patients who initially underwent successful non-operative management of uncomplicated appendicitis. METHODS Potential predictive factors for recurrent appendicitis in terms of clinical characteristics, laboratory data, and abdominal ultrasonography and computed tomography findings, were evaluated. RESULTS This study included 125 patients who underwent initial successful non-operative management of appendicitis. The rate of recurrent appendicitis was 19.2%, and the mean time to recurrence was 12.6 months. Univariate analyses found that rebound tenderness, muscle guarding, appendicoliths, appendiceal diameter >9 mm, and intraluminal appendiceal fluid were associated with recurrent appendicitis. Multivariate analysis identified only intraluminal appendiceal fluid as an independent predictor of recurrent appendicitis. CONCLUSIONS Intraluminal appendiceal fluid is a predictive factor for recurrent appendicitis after initial non-operative management. The results of this study provide valuable information that may help to determine the appropriate management during the first episode of appendicitis.

Predictive factors of negative outcome in initial atropine therapy for infantile hypertrophic pyloric stenosis

The predictive factors of negative outcome in initial i.v. atropine (IA) therapy of infantile hypertrophic pyloric stenosis (IHPS) are unknown. Conservative therapy for IHPS is useful for infants because it does not have the risk of surgical and anesthetic stress, but some cases of atropine therapy result in failure. This study clarified the predictive markers of negative outcome in initial atropine therapy for IHPS.

Histopathologic aspects of endomyocardial biopsy in pediatric patients with idiopathic ventricular tachycardia

Abstract Purpose: The present study aimed to investigate the clinicopathologic findings and histopathologic characteristics of endomyocardial biopsy in pediatric patients with idiopathic ventricular tachycardia.

Oscillatory Variations of Cutaneous Blood Flow in Newborns Using A Laser Doppler Flowmeter

Oscillatory variations of cutaneous blood flow were studied using laser Doppler flowmetry in 20 newborns. Simultaneous monitoring of cardiorespiratory state was also performed. The frequency and amplitude of oscillatory curve varied, even on identical skin regions in each infant. When their respiration and heart rate were irregular, the frequencies of oscillatory curves were significantly higher and with a larger amplitude than when cardiorespiratory function was regular. The frequencies of oscillatory curves at two symmetrical points of an individiual were not different, but a significant difference in the oscillatory cycle was recognized at two asymmetrical points. Distributions of peak‐to‐peak time periods of oscillatory curves were studied in nine healthy and four sick newborns. Seven of nine healthy newborns had more than two peaks in their distributions, while only one peak with a narrowly‐spread distribution was observed in the four sick newborns with almost exclusively periodic breathing throughout monitoring.

Early detection of cutaneous microcirculatory change during hemorrhage using a laser Doppler flowmetry

The purpose of the present study was to evaluate the usefulness of cutaneous microcirculatory monitoring during hemorrhage. We observed changes in cutaneous blood volume, velocity and flow of five adult rabbits during hemorrhage by using a laser Doppler flowmetry. Mean arterial blood pressure, heart rate and blood gas values were measured.

ADRENOCORTICAL CARCINOMA IN INFANCY

A case of adrenocortical carcinoma associated with congenital heart defect in a 6‐month‐old Japanese girl is reported. A fist‐sized tumor was incidentally noted in the right hypochondrium upon admission for cardiac surgery. No clinical endocrinopathy was evident in this case. The resected tumor was encapsulated with smooth surface and no invasion to adjacent tissues or organs was observed. Histologically, the tumor was composed of small cells with granular or clear cytoplasm, and occasional giant cells with single or multiple nuclei. By electron microscopy, the tumor cells showed various nuclear contours with distinct nucleoli and had a moderate amount of cytoplasm containing abundant rough endoplasmic reticulum and mitochondria with variable‐sized electron‐dense granules. Intercellular desmosome‐llke junctions were observed in some tumor cells. Immunohistochemlcally, the tumor cells contained granules positive for estriol, progesterone and Cortisol. These morphological findings including electron microscopic features suggested that the tumor cells had a malignant character.