Mitsunao Kobayashi

Flow-Mediated Vasodilation and Plasma Fibronectin Levels in Preeclampsia

To clarify the vascular endothelial function in pregnant women with hypertensive disorders, we assessed the flow-mediated vasodilation in the radial artery and compared it with plasma fibronectin levels. We determined flow-mediated vasodilation by measuring the change in radial artery diameter during hyperemia in 58 normal pregnant women, 22 preeclamptic pregnant women, and 15 pregnant women with chronic hypertension. In 41 of the 95 pregnant women, we measured the plasma fibronectin levels. Flow-mediated vasodilation in preeclamptic women was significantly less than that in normal pregnant women (P <0.001). In chronic hypertensive women, flow-mediated vasodilation was significantly less than that in normal pregnant women (P <0.001) but more than that in preeclamptic women (P <0.001). Flow-mediated vasodilation showed significant negative correlation with plasma fibronectin levels (P <0.001, r =0.73). Our results indicate that the endothelial function can be noninvasively assessed in pregnant women with hypertensive disorders by measuring the flow-mediated vasodilation of the radial artery with high-resolution ultrasound.

Noninvasive Assessment of Flow-Mediated Vasodilation With 30-MHz Transducer in Pregnant Women

To the Editor: Cockell and Poston (April 1997)1 reported that flow-mediated vasodilation is enhanced in pregnant women but reduced in preeclampsia. They assessed the vasodilation using biopsies of small arteries. Therefore, their assessment was not in vivo but in vitro study. We assessed flow-mediated vasodilation in pregnant women noninvasively. Noninvasive assessment of flow-mediated vasodilation in nonpregnant subjects was first reported by Celermajer et al,2 who measured the brachial artery with high-resolution ultrasound (7.5-MHz transducer). We previously reported that with a 30-MHz transducer it is possible to detect endothelial dysfunction more accurately by measuring the radial artery.3 We examined 60 Japanese women including 20 nonpregnant normotensive healthy women (28.7±5.0 years old), 18 normal pregnant women (31.3±5.0 years old, 35.8±3.1 weeks of pregnancy), and 22 pregnant women with preeclampsia (29.8±3.8 years old, 36.0±3.3 weeks of pregnancy). The diagnosis of preeclampsia was made according to the criteria of the Committee on Terminology of the American Collage of Obstetricians and Gynecologists.4 All 60 subjects were …

Expression of ras GTPase-activating protein (GAP) in human normal chorionic villi and hydatidiform mole

Ras GTPase-activating protein (GAP), an important downregulator of Ras activity, has previously been shown to be abundant in human placenta. The expression of p120 and p100 isoforms of GAP in human normal chorionic villi (n=5) and hydatidiform mole (n=5) was investigated to clarify the involvement of Ras GAP in the growth of chorionic villi in the first trimester of pregnancy. Immunoblot analysis revealed that both p120- and p100-GAP isoforms were remarkably less expressed in mole villi than in normal chorionic villi. The expression of p100-GAP significantly reduced in comparison with that of pl20-GAP in mole villi. Northern blot analysis showed that the amount of GAP mRNA reduced in hydatidiform mole less than one-third of that in normal chorionic villi. The GAP activity, measured by the effect of tissue extract on the hydrolysis of Ras-bound GTP, was significantly lower in hydatidiform mole than in normal chorionic villi. These results suggest that Ras GAP may play an important role in the normal growth and differentiation of human chorionic villi in the first trimester.

Labor and delivery of patients with spinal cord injury

It is possible for obstetric patients with spinal cord injury to give birth vaginally, and cesarean delivery is rarely necessary except for usual w x obstetric indications 1 . They may have many complications, such as autonomic hyperreflexia, which often causes sudden elevation in blood pressure during labor and delivery. We describe two cases of cord-injured parturients who received labor augmentation after placement of epidural catheters. The first patient was a 25-year-old woman in her first pregnancy admitted with a 3 cm dilated cervix at 34 weeks gestation. She had suffered a cord injury at the C level at a diving accident 6 5 years previously. Her pregnancy had been complicated with anemia, recurrent urinary tract infections and autonomic hyperreflexia. At 38 weeks gestation, labor augmentation was carried out under epidural anesthesia and direct monitoring of blood pressure. She uneventfully delivered a

Measurement characteristics of the ultrasound heart rate monitor

It was reported that the measurement error of the fetal heart rate variability (FHRV), which was obtained by a ultrasound heart rate monitor with the Doppler signal, was large even if the auto-correlation technique was used. Nevertheless, fetal heart rate monitoring by the ultrasound heart rate monitor is necessary to determine the status of the fetus because an invasive test cannot be used daily. In order to make sure the quality of the FHRV obtained from the Doppler data, we measured the fetal ECG directly from the fetal sculpture at the same time as the Doppler data. The FHRV differences of the Doppler data from the direct ECG data were found to be concentrated at 0 bpm (beats per minute), around which the pattern of distribution is practically symmetrical. Furthermore, the spectral density of the FHRV differences showed the white spectrum without dominant peaks.<<ETX>>

Ovarian carcinoma in the third trimester

The incidence of ovarian malignancies during pregnancy, although not accurately known, has been reported to average approximately one per w x 25 000 deliveries 1 . In the third trimester, they are difficult to identify because of the enlarged uterus containing the grown-up fetus. We describe two cases of ovarian carcinoma in the third trimester. The first case was detected by ultrasonography Ž . Fig. 1a in a 28-year-old woman at 36 weeks’ gestation of her first pregnancy. Laboratory studies on admission revealed elevated serum alphaŽ fetoprotein 28 848 ngrml; the upper limit of norw x. mal at 36 weekss400 ngrml 2 . The left ovarian tumor was removed on the second postpartum day because of increasing abdominal pain after uneventful vaginal delivery at 37 weeks’ gestation. The tissue diagnosis was an ‘endodermal sinus tumor’ of clinical stage Ic. The second ovarian

Estimation of measurement characteristics of ultrasound fetal heart rate monitor

Ultrasound fetal heart rate monitoring is very useful to determine the status of the fetus because it is noninvasive. In order to ensure the accuracy of the fetal heart rate (FHR) obtained from the ultrasound Doppler data, we measure the fetal electrocardiogram (ECG) directly and obtain the Doppler data simultaneously. The FHR differences of the Doppler data from the direct ECG data are concentrated at 0 bpm (beats per minute), and are practically symmetrical. The distribution is found to be very close to the Students t distribution by the test of goodness of fit with the chi-square test. The spectral density of the FHR differences shows the white noise spectrum without any dominant peaks. Furthermore, the f-n (n>1) fluctuation is observed both with the ultrasound Doppler FHR and with the direct ECG FHR. Thus, it is confirmed that the FHR observation and observation of the f-n (n>1) fluctuation using the ultrasound Doppler FHR are as useful as the direct ECG.

Frequency component of fetal heart rate with integral function method

The authors have been studying the control mechanism of the fetal heart rate using a spectral analysis method which has high accuracy and a short calculation time. They have shown by simulation that frequency components of heart rate variability can be obtained more accurately even if the heart rate data contained certain errors in measurement. They report here the result obtained by applying a similar spectral analysis method to human cardiotocographic data using both the ultrasonic Doppler and the direct scalp electrode method and the integral function method for the analysis. The respiratory component is obtained by spectral analysis.<<ETX>>

Confirmation of the Distribution of Measured Values from an Ultrasound Fetal Heart Rate Monitor

To estimate the measurement error in an ultrasound fetal heart rate (FHR) monitor, we compared the differences in the distribution of the FHR measured with an ultrasound Doppler to the FHR measured with a direct fetal electrocardiogram. We confirm that (1) the distribution is very similar to Students t distribution, and (2) the number of degrees of freedom in Students t distribution has a significant impact on the evaluation of fit.

Effect of Measurement Error of Cardiotocograph to Spectral Analysis

It is reported that the measurement error of the fetal heart rate variability, which is obtained by a cardiotocograph with a Doppler ultrasonics signal, is large even if the auto-correlation technique is used. Simulations are performed to estimate the effect of the measurement error on the spectral analysis. The following two respects are confirmed: (1) when the error is distributed uniformly from -15 msec to +15 msec, the noise level of the spectrum is -12 dB, and (2) the noise level is not greatly different whether the distribution of the measurement error is uniform or Gaussian.