Hideaki Shono

A new method to determine a fractal dimension of non-stationary biological time-serial data

We devised a new analysis using quartile deviation of integrated and subtracted fluctuation, termed QIS-A, to determine a fractal dimension of non-stationary fluctuation. In the algorithm, computations of the quartile deviation, Q(n), of all integrated and subtracted fluctuations are repeated over all scales (n). The fractal scaling exponent is determined as a slope of the line relating log Q(n) to log n. Comparison of the QIS-A and a spectral analysis using 20 computer-simulated fractional Brownian motions demonstrates robustness of the QIS-A to non-stationary fluctuations.

Application of fuzzy logic to the Apgar scoring system

Apgar fuzzy expert system (AFES) applied fuzzy logic to the Apgar Scoring System (APG). We prepared the AFESs for both an inexperienced obstetrician (resident A) and an experienced obstetrician (specialist B) separately. We then compared their evaluations of the same 80 neonates at 1 min after birth using both the AFES and the APG. Analysis of the relationship of the general evaluation by the APG (scores below 6 or over 7) and the AFES (bad or good) to the umbilical arterial blood gases (pH below or above 7.20) showed that the sensitivities were 0.36 for the APG evaluation by resident A, 0.50 for the APG evaluation by specialist B, 0.60 for the AFES rating by resident A, and 0.71 for the AFES rating by specialist B. The specificities were 0.94, 0.95, 0.97 and 0.97, respectively. These results demonstrated that the AFES was capable of reflecting the recognition of the examiner.

Resistance index of uterine artery and placental location in intrauterine growth retardation

BACKGROUND Our aim was to investigate the relationship between placental location and resistance index (RI) of uterine arteries in cases with intrauterine growth retardation (IUGR). METHODS Placental location and flow velocity waveforms of uterine arteries in 86 normal and 20 IUGR cases from 33 to 38 weeks of gestation were examined using a combined real-time scanner and pulsed Doppler ultrasonography. The location of placenta was classified as lateral when most of it was located to either the right or the left side of the uterine midline. Otherwise it was called central. Cases where the placenta was located in the uterine fundus or in the lower segment were not included. RI values were calculated from the uterine arteries on the placental side, on the non-placental side and in case of central placentas as a mean of both uterine arteries. In normal cases, the calculations were done every second week from 33 to 38 weeks of gestation, and the difference in variance among three gestational ages in each artery was tested by a one-way ANOVA. In IUGR cases, a standard deviation score (SDS) was calculated individually in each artery as (RI - normal mean)/normal SD. Differences in SDS between three categories of uterine arteries were examined by non-parametric tests. RESULTS In normal cases, there was no significant difference in variance of RIs among three gestational ages in each category of arteries. In IUGR cases, SDSs on the placental side were higher than those on the non-placental side and those in central placenta, (p<0.01, Wilcoxons and Mann Whitneys tests, respectively). SDSs in five of eight cases with central placentas were below 1.0. Two of 12 cases with lateral placentas had higher SDSs on the non-placental side than on the placental side and resulted in abruptio placentae. CONCLUSIONS Deviation of RIs in uterine arteries with IUGR could be affected by the pathologic conditions of the utero-placental blood flow on the placental side of lateral placenta rather than in central placenta and might be done by dramatic increase in resistance to flow of the myometrial vessels on the non-placental side.

Changes in Auditory Brainstem Responses of Normal Neonates Immediately after Birth

To clarify the functional changes in the acoustic conduction pathway in the human immediately after birth, auditory brainstem responses (ABR) in 58 normal neonates were examined. In longitudinal and cross-sectional analysis, the peak latency of wave 1 showed significant shortening (p less than 0.05) from 1.82 +/- 0.23 ms (mean +/- SD) at 30 min after birth to 1.69 +/- 0.26 ms at 2 h after birth. It continued to decrease gradually therafter. The interpeak latency of waves 1-3 decreased gradually (not significant) from 2.82 +/- 0.19 ms (30 min after birth) to 2.74 +/- 0.15 ms (1 month after birth), while the interpeak latency of waves 3-5 decreased significantly from 2.63 +/- 0.27 ms (30 min after birth) to 2.47 +/- 0.23 ms (24 h after birth; p less than 0.01). These results indicate that functional changes in the acoustic system immediately after birth represent rapid adaptation of the peripheral region to extrauterine environment and development of the more central region.

Chronological changes in subjective symptoms during pregnancy in nulliparous and multiparous women

Background. To investigate chronological changes of subjective symptoms during a normal pregnancy in nulliparous and multiparous women.

Ritodrine-induced agranulocytosis

This is the first reported case of development of agranulocytosis induced by continuous intravenous infusion of a large quantity of ritodrine hydrochloride for tocolysis. It is suspected that the pathophysiological mechanism is a dose‐related toxic reaction and a cell loss maturation process of myelocytes.

The effect of behavioral states on fetal heart rate and middle cerebral artery flow-velocity waveforms in normal full-term fetuses

Objectives: To evaluate the effect of fetal behavioral states on the relationship between fetal heart rate (FHR) and middle cerebral artery resistance index (MCA RI) in normal fetuses. Methods: The FHR and MCA RI of 10 normal cases from 37 to 40 weeks of gestation were recorded consecutively over a 45‐min period. Correlations between the MCA RI and FHR during resting and active phases, classified by an actocardiotocogram, were analyzed by simple regression analysis. Results: The mean FHR and MCA RI were significantly higher during the active phase (140.3 ± 6.6 bpm, 0.79 ± 0.06) than those during the resting phase (137.4 ± 6.8 bpm, 0.75 ± 0.07, P < 0.01, two sample t‐test). There was a significant negative correlation (r = −0.22, n = 2642, P < 0.01) between RI and FHR during the active phase and a significant positive correlation (r = 0.28, n = 2066, P < 0.001) during the resting phase. Conclusions: The relationship between FHR and the MCA RI during the resting phase is different from during the active phase.

Diurnal variation in baseline heart rate of anencephalic fetuses

Abstract The diurnal change in baseline fetal heart rate (FHR) of four anencephalic fetuses at 20, 23, 24 and 30 weeks of gestation were examined. The mean baseline FHR in 00.00–06.00 h, 06.00–12.00 h, 12.00–18.00 h and 18.00–24.00 h were compared by one‐factor ANOVA and Scheffes test in each case. The diurnal variations in baseline FHR were recognized in all subjects (P < 0.01). In 3/4 subjects, the lowest values were at 00.00–06.00 h. The diurnal variation in baseline FHR might be caused by maternal factors because it was present even in the anencephalic fetuses that had no central nervous system having the oscillators of the circadian rhythm.

Diurnal variations in resting-active cycles in full-term fetal heart rate changes

To elucidate the mechanism of the resting-active cycles (RAC) of fetal heart rates (FHR), in the resting and non-resting phases (RP and NRP), 24-h FHR recordings were made on 16 normal full-term pregnant women. RP, NRP, RAC-1 (NRP-NRP cycle), and RAC-2 (RP-RP cycle) were defined based on the criteria of Nijhuis et al. Frequency distributions were plotted separately for the entire 24-h period as well as for the day-time (07:00-21:00 h) and night-time (21:00-07:00 h), and were compared using Kolmogorov-Smirnov two-sample tests. The mean durations (+/- S.D.) (min) of RP, NRP, RAC-1, and RAC-2 were 22.7 +/- 11.2, 67.3 +/- 47.2, 90.0 +/- 47.6, and 89.9 +/- 48.6 during 24-h periods, 20.1 +/- 7.7, 68.3 +/- 52.3, 88.6 +/- 53.1, and 88.4 +/- 53.0 during the day-time, and 25.4 +/- 13.2, 66.2 +/- 41.2, 91.4 +/- 41.0, and 91.5 +/- 43.4 during the night-time. Length of RP was the only factor significantly different during the day and night (P < 0.05). We propose that there are different mechanisms controlling RP and NRP.

Developmental characteristics in sustained fetal tachycardia in 30 to 41 weeks of gestation

The aim of the present study is to reveal gestational age-related changes in sustained foetal tachycardia (SFT). 24 h fetal heart rate (FHR) recordings were made on 102 normal pregnant women in 30-41 weeks of gestation. SFT was defined as an increase for 20 or more beats per minute from the FHR-baseline persisting for more than 20 min. In the results, SFTs in 38-39 weeks started during night-time (1900-0700) more frequently than during day-time (0700-1900) (P < 0.01, by chi-square test). The rate and duration were 0% and 0 min in 30-31 weeks of gestation, and increased to 85% and 114 min in 40-41 weeks, respectively. Two critical points were detected by a piecewise linear regression analysis: in the rate between 34-35 weeks and 36-37 weeks, and in the duration between 38-39 to 40-41 weeks. We conclude that gestational age-related changes in SFT depend on the developmental stages.