Hiroshi Shimokawa

Circadian rhythm of plasma atrial natriuretic peptide, aldosterone, and blood pressure during the third trimester in normal and preeclamptic pregnancies

The influence of pregnancy on circadian variations of plasma atrial natriuretic peptide and aldosterone was studied. In those women with normal pregnancies, the mean 24-hour values of atrial natriuretic peptide and aldosterone increased, compared with the levels in normal nonpregnant subjects. In cases of severe preeclampsia, levels of atrial natriuretic peptide were significantly higher than in the other subjects, but aldosterone levels decreased to nearly those seen in the nonpregnant subjects. Atrial natriuretic peptide did not establish a rhythm in normal nonpregnant and pregnant subjects, but in the studies of aldosterone levels, a clear circadian rhythm was evident. In severe cases of preeclampsia, atrial natriuretic peptide established a circadian rhythm similar to that of blood pressure, and the circadian rhythm of aldosterone disappeared. The main characteristic of the rhythm in atrial natriuretic peptide and blood pressure in women showing preeclamptic signs is that the acrophase occurred at midnight. This evidence suggests that in women with symptoms of preeclampsia the load to the atria increases at midnight.

Unexpectedly low lecithin/sphingomyelin ratio associated with fetal diaphragmatic hernia

Devore GR, Donnerstein RL, Kleinman CS, Platt LD, Hobbins JC. Fetal echocardiography. 1. Normal anatomy as determined by real-time-directed M-mode ultrasound. AMJ OBSTET GYNECOL 1982;144:249-60. Berkowitz RL, Glickman MG, Smith GJW, Siegel NJ, Weiss RM, Mahoney MJ, Hobbins JC. Fetal urinary tract obstruction: what is the role of surgical intervention in utero? AM J OBSTET GYNECOL 1982;144:367-75.

Circadian variations of plasma atrial natriuretic peptide in four types of hypertensive disorder during pregnancy

Summary. Circadian variations in plasma atrial natriuretic peptide were studied, to clarify the characteristic pathophysiology of pregnancy‐induced hypertension (PIH). The mean 24‐h values (range) of atrial natriuretic peptide in mild and severe PIH, pregnancy‐aggravated hypertension, chronic hypertension and normal pregnancy were 130·1 (97·3−207·0), 225·4 (202·8−281·8), 213·1 (183·2−249·5), 81·3 (61·8−116·1) and 77·1 (56·0−123·5) pg/ml, respectively. The values in PIH and pregnancy‐aggravated hypertension were significantly higher, although those in chronic hypertension were no different from normal pregnancy. Plasma atrial natriuretic peptide showed a clear circadian rhythm with acrophase in the middle of the night, in mild and severe PIH. In the other hypertensive disorders, a circadian rhythm could not be confirmed. The results indicate that the elevated values of plasma atrial natriuretic peptide in hypertensive disorders during pregnancy relate to generalized vasoconstriction, and that the diurnal rhythm is a specific characteristic of PIH.

Intrauterine treatment of idiopathic hydrops fetalis.

Seven fetuses with idiopathic hydrops fetalis (IHF) were treated in utero by injecting albumin into the fetal abdominal cavity and by removal of accumulated fluid from the serous cavities. Signs of hydrops fetalis disappeared in utero in one, and skin edema significantly decreased in another. In the other five, signs of hydrops fetalis remained unchanged in utero. The hourly fetal urine production rate (HFUPR) increased after albumin injection in three of five. The interval between the initial diagnosis and delivery ranged from 3 to 14 weeks. Gestational age at the time of delivery ranged from 33 to 40 weeks. There were no stillbirths. Two of three without pleural effusion survived, but four with pleural effusion died of respiratory failure during the neonatal period due to pulmonary hypoplasia. These results indicate that albumin injection into the fetal abdomen in utero deserves further attention and that other therapeutic methods should be established to enhance the development of the lungs in cases of intrauterine treatment of IHF with pleural effusion.

Effects of Intrauterine Treatment on Nonimmunologic Hydrops fetalis

In 44 cases with nonimmunologic hydrops fetalis (NIHF), perinatal management was performed based on our protocol. Twenty-one cases were treated by albumin and/or packed red blood cell (PRC) injection into the fetal abdominal cavity, and 8 cases were treated by transplacental digitalization. Among the cases treated by albumin and/or PRC injection, 5 of 7 cases without pleural effusion recovered in utero, and all 5 cases are alive at the time of writing. However, of 14 cases with pleural effusion, none recovered in utero, and only 1 case is alive. Of 8 cases treated by transplacental digitalization, 2 cases recovered in utero, and 1 case is alive. All fetuses with congenital heart anomaly died. This evidence indicates that albumin and/or PRC injection into the fetal abdominal cavity is an effective procedure for in utero treatment of NIHF without pleural effusion, but suggests that in NIHF resulting from either congenital heart anomaly and/or heart failure, the survival rate may not be increased by transplacental digitalization.

Developmental characteristics of blood flow in the middle cerebral artery in the human fetus in utero, assessed using the linear-array pulsed Doppler method

To evaluate the physiological profile of human cerebral circulation, chronological sequences of flow velocity waveforms in the middle cerebral artery were studied using a pulsed Doppler method. Included were a total of 92 normal fetuses between 27 and 41 weeks of gestation, among which waveforms could be recorded in 81 cases (88.0%). Raw data of the waveforms were analysed by means of two indices: resistance index (RI) and pulsatility index (PI). Both RIs and PIs were calculated at 3-week intervals and were compared at two consecutive periods. Both RI and PI remained unchanged between 27 and 35 weeks of gestation. There were significant decreases in both indices between 33-35 and 36-38 weeks (P less than 0.01), and also between 36-38 and 39-41 weeks (P less than 0.05). These findings indicate that cerebral vascular resistance starts to decrease at the critical period of 36-38 weeks, after which there is a continuing decrease to term. The findings obtained using our method of assessment of fetal middle cerebral artery circulation are discussed.

The characteristics of erythrocyte Na+ transport systems in normal pregnancy and pregnancy-induced hypertension

Objective: To assess the role Na plays in the pathogenesis of pregnancy-induced hypertension (PIH). Methods: We assessed Na and K content, the maximum number of ouabain binding sites, Na+ - L i + countertransport and Na+— K+ cotransport in erythrocytes from women with untreated PIH, normal pregnant women and healthy non-pregnant women. Results: In normal pregnancy, the Na content of erythrocytes decreased, accompanied by the activation of Na excretion systems. In women with PIH, the Na content of erythrocytes and the Na + -K+ cotransport activity significantly increased, whilst erythrocyte K content and the maximum number of ouabain binding sites significantly decreased, compared with observations in normal pregnancy. In both normal pregnancy and PIH, there were no differences in Na+-Li+ countertransport. Conclusions: These results suggest that the increase of erythrocyte Na content in women with PIH may be contributed to by a reduction in the number of ouabain binding sites, whilst Na+-K+ cotransport and Na+ - L i + countertransport may compensate for this effect in women with PIH.

The influence of pleural effusion on pulmonary growth in the human fetus

The present study was performed to clarify the relation of cause and effect between pleural effusion and hypoplastic lung in the human fetus. In six cases with a duration of less than two weeks between the initial diagnosis of pleural effusion and delivery, lung weights were within the mean weight +/- 1.5 S.D. In fourteen cases with a duration of more than two weeks between diagnosis and delivery, seven cases had lungs with weights of less than -2.0 S.D. and twelve had lungs of less than -1.5 S.D. in weight. The incidence of lung weights less than -1.5 S.D. or -2.0 S.D. was significantly higher in cases with a diagnosis-delivery duration of more than two weeks, compared to those with a duration of less than two weeks. These results suggest that the development of hypoplastic lung in fetuses with pleural effusion may depend on the length of the presence of pleural effusion.

Homeothermal Adjustment in the Immediate Postdelivered Infant Monitored by Continuous and Simultaneous Measurement of Core and Peripheral Body Temperatures

To investigate the process of homeothermal acclimation to extrauterine environment, core and peripheral body temperatures in the human neonate were continuously and simultaneously recorded. Twenty-one term-delivered babies were divided into two groups. In group I, 10 babies were kept at 32-34 degrees C for the first 2 h of extrauterine life and at 24-26 degrees C for the succeeding 6 h. In group II, II were kept at 24-26 degrees C for the first 8 h after delivery. Three thermisters were used: one catheter-type placed in the rectum and two involving the zero-heat flow method placed at the sternum and footsole. Because of technical limitations, rectal temperature (Tre) was monitored until temperature in the sternum (Tst) stabilized, after which this transition from Tre to Tst was noted as Tre-st. Changes in resulting temperatures were quantitatively analyzed using Students t test, for both intra- and intergroup comparisons. Tre-st significantly decreased during the first 28 and 42 min for groups I and II, respectively, after which time this temperature rose and stabilized. In group I, the Tre-st reached the homeothermal stage at 2 h 49 min, while 4 h 27 min were required for group II. In group I, the footsole temperature (Tsf) reached a plateau after 2 h 10 min. In group II, Tsf showed a large decrease followed by a slow rise, with no stability achieved during the 8-hour observation period. Intergroup comparisons revealed that the mean Tsf reached conditions not significantly different from those of group I at 6 h 57 min.(ABSTRACT TRUNCATED AT 250 WORDS)

How does pre-eclampsia influence thermal conductivity of the skin?

To evaluate the thermal conductivity characteristics in relation to pre‐eclampsia, deep body temperature (DBT) was measured using the zero‐heat flow method in non‐pregnant healthy subjects, normal pregnant subjects, pregnant subjects with essential hypertension and in pre‐eclamptics. The duration of the initial rise in peripheral DBT was significantly prolonged in the pre‐eclamptics, as compared with findings in the other three groups. The results indicate that pre‐eclamptics have a decrease of thermal conductivity of the skin.