Masahiko Nowatari

Incidence and natural course of trabecular ventricular septal defect: Two-dimensional echocardiography and color Doppler flow imaging study

This study was designed to determine the prevalence of trabecular ventricular septal defect (t-VSD) in neonates and to evaluate the effects of its location, morphologic features, and size on its natural course during infancy. One thousand twenty-eight term newborn infants were examined by color Doppler flow imaging with orthogonal ultrasonographic views. Ten girls and 11 boys (2.0%) were found to have t-VSD. The natural course of the defect was examined in 42 consecutive cases, consisting of this group of 21 neonates and another group of 21 neonates with t-VSD. The morphologic features of the defect within the trabecular septum were classified as one or two defects (36 cases) and as a mesh-like defect (six cases). Reduction in size began from the right ventricular side or from within the trabecular septum. Spontaneous closure occurred most commonly during the first 6 months of life and was observed in 32 cases (76%) by 12 months of age: the frequency of closure was not related to the morphologic features and the initial size of the defect, but apical defects tended to have higher persistent patency than did defects in other locations (p less than 0.05). We conclude that the frequency of t-VSD in neonates and the frequency of spontaneous closure during early infancy are higher than previously believed. This information is important for predicting the natural course of t-VSD and deciding on its proper management.

Regional blood flow distribution and left ventricular output during early neonatal life: A quantitative ultrasonographic assessment

ABSTRACT: To examine the serial changes of left ventricular output and regional blood flow distribution during the early neonatal period, we measured blood flow volume in the ascending aorta, middle cerebral artery, celiac artery, superior mesenteric artery, and renal artery in 23 normal term infants at 1, 4--8, 24, and 96 h after birth. The blood flow volume in each vessel was measured by the pulsed Doppler technique. In the middle cerebral artery, celiac artery, and superior mesenteric artery, the blood flow volume at 1 and 4--8 h of age was significantly lower than after 24 h of age. In contrast, renal artery blood flow volume did not change significantly throughout the study period. The reduced organ blood flow volume soon after birth was related to a low diastolic blood flow in the major vessels, and the percent diastolic integral of blood flow velocity in each vessel showed an inverse linear correlation with the diameter of the ductus arteriosus. The left ventricular output 1 h after birth was 365 ± 69 mL/kg/min, which was significantly higher than after 4-8 h of age. Left ventricular output gradually declined to 301 ± 63 mL/kg/min at 4—8 h of age (p < 0.05 versus 96 h), 272 ± 48 mL/kg/min at 24 h, and 258 ± 54 mL/kg/min at 96 h. There was a significant positive correlation between left ventricular output and the ductus arteriosus diameter. We concluded that 1) there were significant changes in organ blood flow during the period of ductal closure, 2) the high left ventricular output and reduced regional blood flow at 1 and 4—8 h after birth resulted from diastolic left-to-right shunting through the ductus arteriosus, and 3) left ventricular output and regional organ blood flow were not directly related to each other. Our findings on the changes in regional organ blood flow and left ventricular output may provide a useful basis for interpreting abnormal hemodynamics in the early postnatal period.

Effect of the interval between onset of sustained fetal bradycardia and cesarean delivery on long-term neonatal neurologic prognosis

To examine the effect of the interval between onset of sustained fetal bradycardia and cesarean delivery on long‐term neonatal neurologic prognosis.

Micro determination of cortisol and cortisone in umbilical cord blood by chemiluminescent high-performance liquid chromatography

A simple, sensitive and specific chemiluminescent high-performance liquid chromatography method, based on the luminol reaction, for determination of serum cortisol and cortisone, was established. In infants, placental 11beta-hydroxysteroid dehydrogenase type 2 enzyme (11beta-HSD2) activity may affect adrenal function early after birth. The cortisol-cortisone ratio of serum concentrations in umbilical cord blood is an indicator of placental 11beta-HSD2 activity. The optimum conditions for the luminol reaction were determined to be 1.5 mM luminol, 0.6 M sodium hydroxide, 0.15 mm potassium hexacyanoferrate(III) and 200 mM potassium hexacyanoferrate (II). The calibration curves for cortisol and cortisone exhibited good linearity. The correlation coefficients of the calibration curves were 0.996. The intra- and inter-day precisions were in the ranges: cortisol 7.0-12.2 and 4.4-9.2%, cortisone 5.3-7.0 and 6.2-9.9%. The recoveries of these steroids were in the ranges: cortisol 97-105%, cortisone 94-102%. The limits of detection were as follows: cortisol, 0.17 microg/dl; cortisone 0.15 microg/dl. This assay could be successfully applied to determination of the cortisol-cortiosone ratio of serum concentrations in umbilical cord bloods.

GENE STRUCTURE OF THE P100 SERINE-PROTEASE COMPONENT OF THE HUMAN RA-REACTIVE FACTOR

The Ra-reactive factor (RaRF) is a complement dependent anti-microbial factor that reacts with numerous microorganisms such as viruses, bacteria, fungi and protozoa. It is a complex of a mannan-binding lectin (MBL) and the serine protease, P100 (MASPI). P100 activates the C4 component of the complement system and its domain organization is similar to C1r and C1s. In this study, determination was made of the structure of the human P100 gene which was found longer than 67 kbp and to be comprised of 16 exons. Its non-protease region consisted of 10 exons, as in the case of C1r and C1s, and the introns were found present in the boundary separating two CUB domains, an EGF-like domain and two CCP domains and each CUB and CCP domain contained extra internal introns. The serine protease region was comprised of 6 exons in contrast to C1r and C1s, either of which consists of a single exon. The exon-intron structure was found to reflect the evolution of these molecules and P100 to have derived earlier in the stage of evolution than C1r or C1s.