Although many proteases exist in human placenta, their physiological roles are still largely unknown. Our studies showed that these placental proteases metabolize vasoactive and immunomodulating peptides, possibly derived from the fetus, and control the exchange of peptide hormones across the placenta in order to maintain feto-placental homeostasis. We clarified the ...

Echo-planar imaging (EPI) is a form of magnetic resonance imaging (MRI) which acquires images in milliseconds rather than minutes as with conventional MRI. The images produced using EPI are affected by the physiological environment in which the hydrogen atoms producing the signals are found, a process referred to as relaxation. ...

The objectives of this study were to evaluate the transplacental kinetics and effects on placental function of the angiotensin converting enzyme (ACE) inhibitor, enalaprilat, in the dually perfused human placental lobule system. When placed in the maternal perfusate at a high therapeutic serum concentration (150 ng/ml), enalaprilat was rapidly transferred ...

Understanding the physiological regulation of fetal growth is important, as normal variations in size at birth relate to differences in neonatal and adult health. Although fetal growth directly reflects net placental transfer, little is known about how normal fetal growth relates to the transfer capabilities of the placental epithelium, the ...

Straightbred Yorkshire (Y) conceptuses are larger than straightbred Meishan (M) conceptuses throughout gestation and at farrowing. In contrast, when Y and M conceptuses were gestated together in Y recipient females, the birth weight of M pigs was similar to that of their Y littermates. Even though placentae of M pigs ...

Maternal smoking during pregnancy causes reduction of fetal breathing movements, an effect attributed to nicotine in fetal blood. Nicotine is metabolized to cotinine which has a long plasma half-life and exhibits slow clearance across membrane barriers. It is also known to activate placental phospholipase-A2-like enzymes, resulting in formation of prostaglandins. ...

Zidovudine (azidothymidine, AZT) is used in pregnancy to reduce mother to infant transmission of HIV. Understanding the disposition of AZT in the fetus is necessary to optimize therapeutic regimens directed toward the fetus. Recent studies in primates found similar steady-state levels of the glucuronide metabolite of AZT (AZT-glu) in the ...

Progesterone (P4), a major steroid hormone produced by the ovarian corpus luteum (CL) and the placental syncytiotrophoblast, is considered essential for the successful maintenance of mammalian pregnancy. It has been demonstrated in our laboratory and in the laboratories of others, that the baboon (Papio anubis/cynocephalus) is an excellent model for ...

Babies who are small or disproportionate at birth, or who have altered placental growth are now known to have increased rates of coronary heart disease, hypertension and non-insulin-dependent diabetes in adult life. These associations are thought to result from fetal 'programming', whereby a stimulus or insult at a critical, sensitive ...

BACKGROUND: We aim to develop a clinical technique for the non-invasive measurement of placental perfusion, to enable early detection of intrauterine growth restriction (IUGR). Pregnancies with this complication are characterised by low placental perfusion. METHODS: We measured placental perfusion by means of perfusion-sensitive echoplanar imaging (EPI); a rapid method of ...

According to common understanding of sexual differentiation, the formation and development of a penile clitoris in female spotted hyaenas requires the presence of naturally circulating androgens during fetal life. The purpose of the present study was to determine potential source(s) of such fetal androgens by investigating the timing of urogenital ...

We determined the placental transfer of TSH in an in vitro model of dually perfused isolated lobule in 28 human term placentas by adding varying concentrations (5-60 microIU mL(-1)) of TSH as a single bolus dose to the closed maternal circulation. Transmembrane transfer of TSH was also studied by adding ...

The type 2 isoform of 11beta-hydroxysteroid dehydrogenase (11beta-HSD2), which inactivates cortisol (F) to cortisone (E), has been suggested to play a role in the ontogeny of the fetal pituitary-adrenal axis and also protect the developing fetus from the deleterious effects of circulating maternal glucocorticoids. The abundance of 11beta-HSD2 in the ...

That endogenous retrovirus (ERV) is present within the placenta of humans and other mammals has been known for the past 25 years, but the significance of this observation is still not fully understood. Much molecular biological data have emerged in recent years to support the earlier electron microscopic data on ...

Marked changes in the hemostasis system, especially increases in PAI-2, are observed during pregnancy and at delivery. This inhibitor is produced by placental trophoblasts and by macrophages. PAI-2 occurs in two forms, a LMW and a HMW form. LMW PAI-2 is intracellular, HMW PAI-2 is secreted. PAI-2 inhibits both u-PA ...

Human placental lactogen (HPL) is produced in large amounts in normal pregnancies. We report a pregnancy with complete lack of HPL and the placental variant of the human growth hormone HGH-V. The pregnancy resulted in a severely growth-retarded but otherwise normal male baby. PCR analysis of DNA extracted from the ...

The aim of this study is to better understand the relationship between placental pathology and risk of intraventricular hemorrhage (IVH). We address two specific hypotheses. 1) Morphologic correlates of pregnancy-induced hypertension (PIH) are associated with a decreased risk of IVH. 2) Morphologic correlates of amniotic sac inflammation (ASI) are associated ...

The two main groups of placental proteins of ruminants are discussed in this paper: chorionic somatomammotropins (placental lactogens) and pregnancy-specific (-associated) proteins. Placental lactogens belong to the prolactin and growth hormone family. They stimulate mammogenesis, fetal growth and maternal metabolism. Pregnancy-specific proteins and pregnancy-associated glycoproteins belong to the aspartic proteinase ...

This study examined the effects of undernutrition in pregnancy on fetal and placental growth among infants born in 1944-1946 in The Netherlands, including infants born during the war-induced Dutch famine of 1944-1945. There was an increase in placental weight, but not in birthweight, in infants whose mothers' nutrition was compromised ...

Previous studies have demonstrated the presence of D2-dopamine binding sites in the human placenta, and that dopamine (DA), via these D2-like receptors, inhibits both basal- and hormone-stimulated secretion of human placental lactogen (hPL) from trophoblastic cells. However, nothing is known about the ontogenesis of this placental D2-dopamine receptor (D2R) during ...

In this study, we determined the concentrations of acidic lipids, including cholesterol sulfate (CS), sulfatide and GM3 ganglioside, in human sera of non-pregnant state and during the course of pregnancy. In human sera of non-pregnant women, GM3 was present at a concentration of 8 nmol/ml and the concentrations of CS ...

We tested the hypothesis that chronic maternal GH administration would increase fetal substrate supply, increase maternal and fetal insulin-like growth factor I (IGF-I) concentrations, and therefore enhance growth in the late gestation fetal sheep. Eleven ewes received bovine GH 0.1 mg/kg twice daily for 10 days, whereas 10 control ewes ...

The calculation of radiation dose estimates to the fetus is often important in nuclear medicine. To obtain the best estimates of radiation dose to the fetus, the best biological and physical models should be employed. In this paper the most recent data available on the placental crossover of many radiopharmaceuticals ...

The placenta is essential for normal fetal development. Failure of the placenta can result in many fetal conditions, for example, intrauterine growth retardation (IUGR). Placentas from pregnancies complicated by IUGR show vascular damage, which may lead to the onset of pregnancy-induced maternal hypertension. Accurate placental assessment may, therefore, indicate which ...

In pregnancy, the human placenta GH acts as a growth-promoting hormone and appears to be the main stimulator of insulin-like growth factor I (IGF-I) secretion. In a woman with a TSH-secreting macroadenoma, successful treatment with the somatostatin analog octreotide was conducted during the first month and the second half of ...

The increasing practice of preterm delivery in the fetal interest for conditions such as pre-eclampsia or intrauterine growth restriction (IUGR) has provided an opportunity to study placental structure in pregnancies with prenatal evidence of fetal compromise. These data suggest that the origin of fetal hypoxia in IUGR with absent end-diastolic ...

OBJECTIVE: To assess the effect of having a placental abruption on 1. the probability of having further pregnancies, and 2. the rate of recurrence in such pregnancies. DESIGN: A cohort study based on the Medical Birth Registry of Norway. RESULTS: From 1967 to 1989, placental abruption occurred in 218/4951 subsequent ...

We present two pregnancies associated with normal live births and the unusual concomitance of chorangioma and placental vascular malformation with mesenchymal hyperplasia. The enlarged placenta had the characteristic findings of chorangioma, dilated and varicose chorionic vessels and multiple vesicle-like villi containing hyaluronic acid. The vesicle-like villi showed diploid cellular DNA ...

AIMS: To evaluate the relation between Chlamydia trachomatis infection and stillbirth, placental tissue was studied for the presence of C trachomatis. METHODS: Paraffin wax embedded placental tissue of a stillbirth fetus, born at the 36th week of gestation to a 21 year old mother with high serum antibody titres to ...

During mammalian pregnancy, the circulating concentration of cortisol (in rodents, corticosterone) in the mother is much higher than that in the fetus. Since the placenta is the only barrier, apart from the uterus, between the mother and her fetus, this gradient in cortisol concentrations suggests that there is a placental ...

This study was designed to examine the cellular localization and developmental regulation of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) type 1 gene expression in the ovine placenta. Placental tissues were collected at discrete times between days 59 and 143 of pregnancy (term = 145 days). Levels of 11 beta-HSD1 mRNA were ...

To determine whether placental ratio is influenced by maternal anaemia, a retrospective observational study was performed in a regional tertiary hospital in Hong Kong. The gestational age, birthweight, placental weight, and placental ratio were studied in 152 mothers with anaemia due to thalassaemia trait, 232 mothers with anaemia due to ...

The pregnancy syndrome preeclampsia is associated with placental dysfunction, dyslipidemia, and endothelial cell activation, and is a major cause of maternal and fetal morbidity and mortality. In this report, a nested case-control study of matched preeclamptic and normal pregnant women was used to investigate the association of maternal and fetal ...

Placenta in mouse generate increasing quantities of superoxide dismutase from day 13 of pregnancy until parturition. This is associated with a concomitant reduction in the activity of superoxide radical. This findings points to the steroidogenic control of the later half of pregnancy by the placental axis. Parturition is associated with ...

OBJECTIVES: The study aims were to conclusively demonstrate apoptosis in the human placenta and to quantify its incidence at different stages of pregnancy. STUDY DESIGN: Placental samples were obtained from 28 first-trimester pregnancies and 38 uncomplicated third-trimester pregnancies. Light microscopy, electron microscopy, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate marker nick ...

Placental transport and fetoplacental utilization of threonine (Thr) were compared at 130 +/- 1 days gestational age between seven control ewes (C) and six ewes in which intrauterine growth restriction (IUGR) had been induced by exposure to high ambient temperature from 33 +/- 1 to 112 +/- 2 days of ...

OBJECTIVE: Our purpose was to assess the effect of intravenous zidovudine on placental function and fetal well-being. STUDY DESIGN: Eighteen chronically instrumented third-trimester pregnant baboons and their fetuses were studied after 4- to 48-hour infusions of zidovudine to 14 mothers (0.8 to 2.0 mg/kg/hr) and 6 fetuses (0.2 to 0.22 ...

Placental lesions are difficult to assess because there is often a discrepancy between the ultrasound findings, clinical diagnosis and pathology. Large placental lesions especially when solid and echogenic on ultrasound may be associated with a high maternal serum alpha-fetoprotein, intrauterine growth retardation or uteroplacental insufficiency. We report three cases in ...

Fetal cardiovascular control is effected by an interaction of the fetal somatic and placental circulations. Three primary regulatory mechanisms are involved: transplacental transfer of extracellular fluid, driven by a difference in hydrostatic and oncotic pressures; modulation of fetal placental and somatic vascular resistances by means of blood pressure controlled production ...

The objective of this study was to evaluate the effect of increased circulating endothelin on fetal and placental growth in the rat. Indwelling arterial and venous catheters were placed on day 14 of a 22-day gestation in timed-pregnant Sprague-Dawley rats. Saline, 0.2 nmol/kg/h endothelin, or 0.5 nmol/kg/h endothelin was continuously ...

Effects of restricting uterine space on physical, biochemical, and histochemical characteristics of ovine placental tissues were studied. Ewes (n = 20) were unilaterally ovariectomized, assigned to either control (C; n = 10) or unilateral (UPx; n = 10) pregnancy groups, mated (d 0), and hysterectomized on either d 60, 90, ...

We report on a large asymptomatic placental chorioangioma, identified as an area of reduced echogenicity on ultrasound at 36 weeks' gestation. Despite the large size, it was not associated with the usual maternal or fetal complications expected with a chorioangioma of that size, possibly because of thrombosis and tumour degeneration.

In subinvolution of the placental bed, the uteroplacental (spiral) arteries that had undergone physiologic changes to accommodate the needs of the placenta and fetus during pregnancy fail to involute and avert to their nonpregnant state. Because expression of bcl-2 oncoprotein is associated with inhibition of apoptosis and prolonged cell survival, ...

PROBLEM: In investigating possible immunologic causes of miscarriage, we hypothesized a more frequent maternal immune response in placental tissue in women miscarrying their first pregnancy, compared to woman miscarrying following at least one full-term delivery. METHOD OF STUDY: We reviewed the medical charts of 273 consecutive women who had treatment ...

Multiple exposures to AZT (Zidovudine) for 14 hr were examined in the dually perfused human term placental lobule in order to determine the pharmacokinetics of transfer, as well as several viability parameters of toxicity. In each experiment, three separate additions of AZT at a concentration of 3.8 mM was added ...

The purpose of this study was to determine the primary form of human placental norepinephrine transporter (hNET) mRNA expressed in the human placenta and to compare the level of expression in normal pregnancies and in pregnancies complicated by drug exposure or other forms of physiological derangement. We used the hNET ...

Cocaethylene is produced by transesterification of cocaine in the presence of ethanol, and there is evidence that it is more neurotoxic than cocaine. Because many women of reproductive age use cocaine and because many cocaine users also consume alcohol, the fetal toxicology of cocaethylene is of great concern. At the ...

To determine if the placental weight to birthweight ratio (placental ratio) is increased in pregnancies complicated by diet-treated gestational impaired glucose tolerance (IGT) and diabetic (GDM) pregnancies, a retrospective case control study was performed on 478 singleton IGT/GDM pregnancies delivered in 1994 and compared with a control group that consisted ...

OBJECTIVE: Placental 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), which converts active cortisol to inactive cortisone, has been proposed to be the mechanism guarding the fetus from the growth retarding effects of maternal glucocorticoids; however, other placental enzymes have also been implicated. Placental 11 beta-HSD is unstable in vitro, and enzyme activity ...

Our aim was to evaluate the isolated placental lobule to study maternofetal transplacental digoxin transfer and accumulation in placental tissue in vitro. Digoxin passage across the isolated lobule of 10 human placentas was calculated from repeated fetal and maternal perfusate samples, and placental tissue digoxin concentrations were measured at the ...