Biomedical subjects
Publications and source records attributed to Yoko Honma.
A case of monochorionic twin boys delivered at 34 weeks of gestation following induced ovulation with clomiphene is described. One twin was typed as blood group AB and the other as B. Flow cytometry showed blood group chimerism. DNA polymorphism analysis of peripheral lymphocytes and hair root cells showed that the chimerism was confined to the blood cells and they were dizygotic.
We assessed ventricular volume with three-dimensional ultrasonography. The study group consisted of 54 infants admitted to the neonatal intensive care unit (NICU). Gestational age was 32.9+/-3.5 weeks and birth weight was 1774+/-623 g. To obtain images, the transducer was placed on the anterior fontanel. Sagittal sections were serially and automatically scanned from left to right. The angle of scanning was 60 degrees and five seconds were spent on e scanning. Two hundred fifty B-mode images were stored in the built-in computer for later retrieval. We chose the parasagittal sections from the midline to the lateral portion and traced manually an area of the lateral ventricle in each section at intervals of 1 mm. The built-in computer integrated them and measured the ventricular volume. The lateral ventricular size became larger during the first two weeks after birth. The left ventricle was larger than the right one. There was no correlation between lateral ventricular volume and birth weight. Our study shows the normal value of the lateral ventricular volume in neonates.
The purpose of this study was to assess cardiac function of newborns with mild asphyxia by a Doppler-derived index combining systolic and diastolic performance (Tei index). We studied 20 preterm infants with mild asphyxia. A control group consisted of 20 gestational age-matched preterm infants without asphyxia. Echocardiograms were performed during the fourth and seventh days after birth. Peak velocities of an early filling wave (E) and an atrial contraction wave (A) were measured from the mitral inflow velocity profile and the ratio of peak E to A was calculated. Ejection time was measured from the left ventricular outflow Doppler signal. The sum of isovolumetric times was obtained by subtracting the ejection time from the interval between cessation and onset of mitral inflow. The index was the sum of isovolumetric times divided by ejection time. Ejection fraction was also calculated. The ratio of peak E to A and ejection fraction were the same in both groups. The myocardial performance index in patients with asphyxia was higher than that in patients without asphyxia. We concluded that patients with mild asphyxia have a mild cardiac dysfunction and this change can be detected by a myocardial performance index.
The purpose of this study was to examine whether dichorionic twins conceived by assisted reproductive technology (ART; intracytoplasmic sperm injection [ICSI], in vitro fertilization [IVF], gamete-intrafallopian tube transfer [GIFT]) have a higher risk of birth defects compared to dichorionic twins conceived naturally. We reviewed the medical records of 406 mothers with dichorionic twin pregnancies, who received continuous antenatal care from < or = 20 weeks of gestation and gave birth to infants after > or = 24 weeks of gestation in our institute. Birth defects were diagnosed at the time of hospital discharge according to the International Classification of Diseases, 10th Revision. Occurrence of birth defects was compared between twins conceived by ART and those conceived naturally using logistic regression analysis. Overall, 51 of 812 infants (51/812 = 6.2%) had birth defects. The incidence of birth defects in ART-conceived twins was significantly higher than that of naturally conceived twins with an odds ratio of 6.9 (95% confidence interval [CI] 2.1, 22.5), 3.7 (95% CI 1.2, 12.0), and 4.3 (95% CI 1.4, 14.3) for ICSI, IVF, and GIFT, respectively. The higher frequency of birth defects in ART-conceived twins was still significant after adjusting for higher maternal age in the ART group, with an adjusted odds ratio of 6.7 (95% CI 2.1, 21.9), 3.6 (95% CI 1.1, 11.5), and 3.7 (95% CI 1.2-11.8) for ICSI, IVF, and GIFT, respectively. Dichorionic twins conceived by ART, compared to dichorionic twins conceived naturally, had a much higher risk for birth defects diagnosed at hospital discharge.
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The objective of this study is to determine the causes of asymmetry of the lateral ventricles in neonates. We also studied the effect of head position and the relationship of body weight at birth in regard to lateral ventricular size. Eligible for inclusion in this study were 60 neonatal infants whose gestational age was 33.1+/-3.5 weeks and whose birth weight was 1793+/-613 g. Ultrasonographic examinations were performed at the first and the second weeks after birth. In parasagittal and coronal scans through the posterior horn of the lateral ventricle, the lateral ventricle was traced and its area was measured. We found no significant variation of ventricular size in relation to body weight at birth. The left ventricular size was larger than the right one. The difference of the left and right ventricular sizes was partially effected by head position. The ratio of left to right lateral ventricular sizes showed a very wide distribution. We considered that ventricular asymmetry is not pathological, but due to individual differences.
The objective of this study is to determine the difference of the flow velocities of left and right cerebral arteries. We also studied the effect of head position to the cerebral arterial flow velocities. Eligible for inclusion in this study were 60 neonatal infants whose gestational age was 33.1+/-3.5 weeks and whose birth weight was 1793+/-613 g. The ultrasonographic examinations were performed in the first and second weeks after birth. In an axial scan through a temporal window, the Doppler sample volume was positioned at the center of the M1 portion of the middle cerebral artery and the flow velocity curve was detected. No statistical difference was seen in the flow velocities between the left and right middle cerebral arteries. However, the flow velocities in the upper side were significantly higher than those in the lower side. RI in the upper side was significantly smaller than that in the lower one. This change of flow velocities stabilized in 5 min after the head was turned upside down. The effect of head positioning to the intracranial blood flow must be considered when cerebral ultrasonography of neonates is performed.