The relationship between Doppler indices from inferior vena cava and hepatic veins in normal human fetuses.

This study was conducted to determine the gestational age-related reference range of the preload index [peak velocity during atrial contraction (A)/peak velocity during ventricular systole (S)] for the inferior vena cava (IVC), the right hepatic vein, the middle hepatic vein and the left hepatic vein. The slope and the intercept of the regression line for each preload index were compared among the 4 veins using analysis of covariance. Doppler measurements were obtained for the 4 veins of 316 normal fetuses at 22-40 weeks of gestation. A and S values were measured from the recorded flow velocity waveform of each vein and the A/S ratio was calculated as the preload index. The regression lines for the preload index of the 4 veins decreased gradually throughout gestation. Analysis of covariance revealed no significant differences in the slopes of the regression lines for the 4 veins. However, the intercepts of the regression lines for all hepatic veins were significantly higher than that of the regression line for the IVC (P&#60;0.0001), with the difference ranging from 0.024 to 0.033. There were no significant differences among the intercepts of the regression lines for different hepatic veins. We concluded that the relationship between the preload index and the duration of gestation was statistically similar for all hepatic veins, and strongly resembled that for the IVC.</p

On Subject Aux Inversion

0. Subject Aux Inversion (henceforth SAI) is a rule which inverts the order of subject and auxiliary. For example, it converts a sentence John would be happy into the corresponding interrogative Would John be happy? ..

Effects of L-dopa or dopamine on human decidual prostaglandin synthesis.

L-Dopa and three catecholamines in the amniotic fluid before and after labor were measured to confirm the amniotic fluid catecholamine levels at the end of gestation. L-Dopa values were higher than those of three catecholamines, and dopamine which was the predominant catecholamine, rose significantly after the onset of labor. Then, to evaluate the effects of L-dopa or dopamine on prostaglandin synthesis, strips of human decidua vera obtained from fetal membranes at the time of elective cesarean sections before the onset of labor were incubated in Krebs-Ringer buffer in the presence of L-dopa or dopamine. When L-dopa was added, the net production of prostaglandin(PG)F was significantly greater than that of the control at each incubation time. On the other hand, the significant rise was observed only after 10 min of incubation for PGE2 production. Dopamine had a stimulatory effect on PGF synthesis only after 15 and 30 min of incubation, and it also stimulated the release of PGE2 at each incubation time. These results suggest that dopamine and L-dopa in amniotic fluid stimulate the production of prostaglandin by the decidua in humans.</p

The Optimal Prepregnancy Body Mass Index for Lactation in Japanese Women with Neonatal Separation as Analyzed by a Differential Equation

We used a differential equation to identify the biological relationship between the maternal prepregnancy body mass index (BMI) and lactation on postpartum day 4 in Japanese women with neonatal separation. This retro-spective observational study included 252 mothers (135 primiparas, 117 multiparas) whose singleton neonates were admitted to a neonatal ICU. We formulated hypotheses based on breast anatomy to analyze the relation-ship between the expressed milk obtained on postpartum day 4 and the maternal prepregnancy BMI with the following differential equation: y’(x) = k y(x)/x, where k is the constant, x is the prepregnancy BMI, and y is the expressed milk volume. The formula was then obtained as y(x) = axk, where a is the constant. The Akaike information criterion (AIC) was used to estimate the regression equation with the maximum likelihood for primiparas and multiparas. The best criteria for BMI determined by the AIC were 20.89 kg/m2 in primiparas and 20.19 kg/m2 in multiparas. These were the optimal BMI values for lactation, coinciding with the median prepregnancy BMI in the study population (20.78 kg/m2 in primiparas and 20.06 kg/m2 in multiparas). The formula based on biomathematics might help establish the biological relationship between prepregnancy BMI and breastmilk volume

Fetal and neonatal excretion of free and conjugated ritodrine.

The ability of the human fetus and neonate to conjugate and excrete ritodrine, a beta 2-sympathomimetic drug, was investigated. Free and conjugated ritodrine concentrations in the plasma, amniotic fluid and urine were measured in 11 mother-infant pairs, to whom intravenous ritodrine had been administered before elective cesarean section at term. Ritodrine was determined by HPLC with electrochemical detection. At delivery, conjugated ritodrine values were significantly higher than those for the free form in maternal and fetal plasma. There were significant positive correlations between the concentrations in the maternal and umbilical vein plasma for both free and conjugated ritodrine. In the amniotic fluid, the total ritodrine concentrations were much higher than those in the fetal plasma, the conjugated form accounting for 90.2% of the total. Furthermore, the percentages of conjugated ritodrine in the amniotic fluid and neonatal urine were significantly higher than the percentage in the maternal urine on the day of birth. In the neonatal urine, the concentrations of free and conjugated ritodrine decreased rapidly after birth as did those in the maternal urine, on day 3 postpartum being less than 2% of the values on the day of parturition. These results indicate that the fetus at term is capable of forming conjugated metabolites of ritodrine and of excreting free and conjugated ritodrine in its urine.</p

Fetal Cerebellar Growth Curves Based on Biomathematics in Normally Developing Japanese Fetuses and Fetuses with Trisomy 18

We used biomathematics to describe and compare cerebellar growth in normally developing and trisomy 18 Japanese fetuses. This retrospective study included 407 singleton pregnancies with fetuses at 14-39 weeks of gestation and 33 fetuses with trisomy 18 at 17-35 weeks. We used ultrasonography to measure fetal transverse cerebellar diameter (TCD) and anteroposterior cerebellar diameter (APCD). We hypothesized that cerebellar growth is proportional to cerebellar length at any given time point. We determined the formula L(t) ≒Keat+r, where e is Napier’s number, t is time, L is cerebellar length, and a, K, and r are constants. We then obtained regression functions for each TCD and APCD in all fetuses. The regression equations for TCD and APCD values in normal fetuses, expressed as exponential functions, were TCD(t)=27.85e0.02788t−28.62 (mm) (adjusted R2=0.997), and APCD(t)=324.29e0.00286t−322.62 (mm) (adjusted R2=0.995). These functions indicated that TCD and APCD grew at constant rates of 2.788%/week and 0.286%/week, respectively, throughout gestation. TCD (0.0153%/week) and APCD (0.000430%/week) grew more slowly in trisomy 18 fetuses. This study demonstrates the potential of biomathematics in clinical research and may aid in biological understanding of fetal cerebellar growth

Formulae Based on Biomathematics to Estimate the Standard Value of Fetal Growth of Japanese

We devised biomathematics-based formulae to estimate the standard values of fetal growth of Japanese after 22 weeks' gestation. The growth rates of bi-parietal diameter (BPD), abdominal circumference (AC), femur length (FL), and estimated fetal body weight (EFBW) at the time of gestation were assumed to be proportional to the product of the value at the time and the rest value of an unknown maximum value, respectively. The EFBW was also assumed to follow a multiple logistic function of BPD, AC and FL to fit the standard values of Japanese fetuses published by the Japan Society of Ultrasonics in Medicine. The Mann-Whitney test was used for statistical analysis. The values as a function of gestational day, t, were as follows: BPD(t)=99.6/(1+exp (2.725−0.01837＊t)) (mm); AC(t)=39.7/(1+exp (2.454−0.01379＊t)) (cm); FL(t)=79.6/(1+exp (2.851−0.01710＊t)) (mm); EFBW(t)=8045.1/(1+exp (6.028−0.06582＊BPD(t)−0.1469＊AC(t)+ 0.07377＊FL(t))) (g). EFBW as a function of BPD, AC and FL was as follows: EFBW=8045.1/(1+exp (4.747+ 0.02584＊BPD+0.1010＊AC−0.1416＊FL)) (g). When the BPD, AC and FL were at −2 standard deviation (SD), −1SD, mean and + 2SD, the EFBW values calculated by the formula were statistically closer to the standard values than conventional formulas with p-values of 4.871×10−7, 4.228×10−7, 9.777×10−7 and 0.028, respectively. The formulae based on biomathematics might be useful to estimate the fetal growth standard values