epidermal-growth-factor and Pre-Eclampsia

Preeclampsia is a hypertensive disorder of pregnancy, responsible for over 60 000 maternal deaths annually. Endothelial dysfunction is a central aspect to its pathophysiology, and currently, no medical therapeutic is available for its treatment. In this study, we aim to investigate the effect of epidermal growth factor (EGF) on endothelial dysfunction using primary human tissues. We performed a number of in vitro assays that mimic the vascular endothelial dysfunction that occurs in preeclampsia. Epidermal growth factor reduced the expression of vascular cell adhesion molecule-1, a marker of endothelial dysfunction, after insult with tumor necrosis factor α (TNF-α) or serum from women with preeclampsia. Additionally, after TNF-α insult, EGF reduced tube disruption and the adhesion of monocytes to primary human umbilical vein endothelial cells (HUVECs). Our findings suggest that EGF reduces endothelial dysfunction in primary HUVECs. Epidermal growth factor may have potential as a novel peptide treatment for preeclampsia and other diseases where there is endothelial dysfunction.

Topics: Endothelium, Vascular; Epidermal Growth Factor; Female; Human Umbilical Vein Endothelial Cells; Humans; Monocytes; Pre-Eclampsia; Pregnancy; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

During pregnancy, trophoblast cell invasion needs to be finely controlled. Aberrant trophoblast cell invasion is associated with placental diseases. Epidermal growth factor (EGF) and its receptor, EGFR, are expressed in trophoblast cells. Although the pro-invasive effect of EGF on trophoblast cells has been reported, the underlying mechanism remains largely unknown.. In the present study, we conducted an RNA sequencing (RNA-seq) to HTR-8/SVneo human trophoblast cells in response to EGF and identified KISS1 as a target gene of EGF. The human KISS1 gene encodes kisspeptin, also known as metastin, which can suppress tumor metastasis. Our results showed that EGF treatment downregulated KISS1 expression and secretion by activating the EGFR-mediated PI3K/AKT signaling pathway. In addition, the expression of inhibitor of DNA-binding protein 3 (ID3) was downregulated by EGF and that was required for the EGF-suppressed KISS1 expression. Functionally, transwell invasion assays demonstrated that EGF stimulated human trophoblast cell invasion by downregulating KISS1 expression. Preeclampsia (PE) is a placental disease characterized by insufficient trophoblast cell invasion. Our clinical results revealed that serum levels of EGF were downregulated while serum and placental levels of KISS1 were upregulated in PE patients.. This study demonstrates that downregulation of EGF can lead to poor trophoblast cell invasion by increasing KISS1 expression which subsequently contributes to the pathogenesis of PE. Video Abstract.

Topics: Cell Movement; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Inhibitor of Differentiation Proteins; Kisspeptins; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Phosphatidylinositol 3-Kinases; Placenta; Placenta Diseases; Pre-Eclampsia; Pregnancy; Proto-Oncogene Proteins c-akt; Signal Transduction; Trophoblasts

Preeclampsia is associated with reduced pro-angiogenic Placental Growth Factor (PlGF) and increased levels of anti-angiogenic soluble FMS like tyrosine kinase-1 (sFlt-1). We have previously shown that sFlt-1 secretion is positively regulated via the Epidermal Growth Factor Receptor (EGFR) and mitochondrial respiration pathways. We assessed whether these pathways also regulate endothelial and placental secretion of PlGF.. Primary cytotrophoblast cells and primary human umbilical vein endothelial cells (HUVECs) were treated with EGFR inhibitor gefitinib, or small molecules that inhibit down-stream pathways of the receptor: U0126, PD98059 (ERK/MEK pathway inhibitors), ZM336372 (JAK/STAT inhibitor) or AG490 (JAK inhibitor). We inhibited mitochondrial respiration in primary cytotrophoblasts using mitochondrial complex inhibitors rotenone (complex I), antimycin (complex III) or oligomycin (complex IV). We then measured PlGF secretion in the condition media.. Three inhibitors of the EGFR pathway significantly increased PlGF secretion: gefitinib (p = 0.03), AG490 (p < 0.0001) and U0126 (p = 0.03) in primary cytotrophoblasts, while PD98059 reduced PlGF secretion (p = 0.002). In the same cells, neither gefitinib or UO126 altered PlGF mRNA expression, but AG490 significantly increased its expression (p = 0.02). Primary endothelial cell PlGF secretion was significantly reduced when treated with PD98059 and U0126 while ZM336372 had no effect. Rotenone significantly reduced cytotrophoblast PlGF secretion (p = 0.0005). Neither antimycin (p = 0.9) or oligomycin (p = 0.9) had an effect.. We have shown that PlGF secretion from primary cytotrophoblast and HUVECs is altered by inhibiting EGFR signaling and potentially mitochondrial respiration, coincident with reduced sFlt-1 secretion. This suggests that common pathways are regulating both pro and anti-angiogenic molecules that are changed in association with preeclampsia and provides insight into the pathogenesis of this serious disease.

Topics: Adult; Enzyme Inhibitors; Epidermal Growth Factor; Female; Gefitinib; Gene Expression Regulation; Human Umbilical Vein Endothelial Cells; Humans; Placenta; Placenta Growth Factor; Pre-Eclampsia; Pregnancy; Protein Kinase Inhibitors; Signal Transduction; Trophoblasts

Epidermal growth factor (EGF) and Hepatocyte growth factor (HGF) both have tyrosine kinase receptors (EGFR and c-Met) which upon binding, activates and regulates many important cellular processes such as cell survival, growth, proliferation, differentiation, invasion, repair and so forth via the RAS/MAPK/ERK1/2, PI3K/AKT and JAK STAT3 pathways. These processes are crucial for the development of a placenta and other functions in order for a normal pregnancy to occur. Hence, this study determined the concentrations of HGF and EGF to find the correlation between HIV and preeclampsia (PE).. A total sample size of n = 80 was used, n = 40 preeclamptic women and n = 40 normotensive women these were further stratified into HIV-positive and HIV-negative women. Analysis of the growth factors were done by using the multiplex Bio-Plex immunoassay method.. Irrespective of HIV status, based on pregnancy type, EGF in PE women displayed an upregulation compared to normotensive women. However, for HGF no variance was found between pregnancy type. Based on HIV status, regardless of pregnancy type, both HGF and EGF levels were significantly increased in HIV-positive women compared to HIV-negative women. Across all groups for HGF, significant difference was found between HIV-negative normotensive women (lower) vs HIV-positive normotensive women (higher). Nevertheless, for EGF across all groups, a statistically significant decrease was found in HIV-negative normotensive women compared to HIV-positive normotensive women, HIV-positive PE women and HIV-negative PE women.. The study demonstrates that there is a strong association between HIV and PE and that HGF and EGF are promising biomarkers to use as a diagnostic tool for PE.

Topics: Adolescent; Adult; Biomarkers; Epidermal Growth Factor; Female; Hepatocyte Growth Factor; HIV Infections; Humans; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Infectious; Retrospective Studies; Young Adult

The placenta is arguably the most anatomically variable organ in mammals even though its primary function is conserved.. Using RNA-Seq, we measured the expression profiles of 55 term placentas of 14 species of mammals representing all major eutherian superordinal clades and marsupials, and compared the evolution of expression across clades.. We identified a set of 115 core genes which is expressed (FPKM ≥10) in all eutherian placentas, including genes with immune-modulating properties (ANXA2, ANXA1, S100A11, S100A10, and LGALS1), cell-cell interactions (LAMC1, LUM, and LGALS1), invasion (GRB2 and RALB) and syncytialization (ANXA5 and ANXA1). We also identified multiple pre-eclampsia associated genes which are differentially expressed in Homo sapiens when compared to the other 13 species. Multiple genes are significantly associated with placenta morphology, including EREG and WNT5A which are both associated with placental shape.. 115 genes are important for the core functions of the placenta in all eutherian species analyzed. The molecular functions and pathways enriched in the core placenta align with the evolutionarily conserved functionality of the placenta.

Topics: Actins; Animals; Annexins; Biological Evolution; Cattle; Dogs; Epidermal Growth Factor; Female; Humans; Mammals; Mice; Placenta; Pre-Eclampsia; Pregnancy; Transcriptome

To investigate proliferation, EGF and EGFR expression of villous trophoblast (VTB), decidual cells (DC), and extravillous trophoblast (EVTB) in the placentas from pregnancies complicated with preeclampsia (PE) and to compare them with placentas from normal pregnancies.. Twenty-nine PE placentas and 19 control placentas were studied for EGF and EGFR immunohistochemical expression (noted as week, moderate or strong). Proliferation was expressed as the proliferation index. The CK7 antibody was used to distinguish DC from EVTB.. DC and EVTB proliferation was significantly higher in PE placentas. EGFR and EGF expression showed no significant difference.. Higher DC and EVTB proliferation in PE could contribute to PE development.

Topics: Adult; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Placenta; Pre-Eclampsia; Pregnancy; Trophoblasts

The epidermal growth factor (EGF) signaling system regulates trophoblast differentiation, and its disruption could contribute to perinatal disease. We hypothesized that this pathway is altered in preeclampsia, a disorder associated with trophoblast apoptosis and failure to invade and remodel the uterine spiral arteries.. Six EGF family peptides and a truncated EGF receptor splice variant (p110/EGFR) were examined using immunohistochemistry in the trophoblast of placentas (N = 76) from women with preeclampsia, and compared to placentas from women of similar gestational age (GA) with preterm labor (PTL) or small for gestational age (SGA) fetuses, as well as normal term placentas. EGF, transforming growth factor-α (TGFA), and heparin-binding EGF-like growth factor (HBEGF) were evaluated using ELISA in maternal plasma from another 20 pregnancies with or without preeclampsia. Cell death was evaluated in the HTR-8/SVneo human cytotrophoblast cell line using TUNEL to evaluate the protective effects of EGF peptides.. Trophoblast HBEGF, TGFA, and EGF were significantly reduced in preeclampsia compared to PTL and SGA, while p110/EGFR accumulated significantly on the surface of the chorionic villi (p < 0.05). Plasma EGF levels were significantly decreased in preeclamptic patients, compared to non-preeclamptic patients (p < 0.05). HBEGF, EGF, TGFA, epiregulin, and betacellulin each blocked cytotrophoblast cell death in vitro (p < 0.05).. Three members of the EGF family are dysregulated in placentas with preeclampsia, whereas p110/EGFR, a potential EGF receptor antagonist, is overexpressed. These findings are consistent with the concept that disruption of the EGF signaling system contributes to aberrant trophoblast development associated with preeclampsia.

Topics: Adult; Apoptosis; Cell Line, Transformed; Chorionic Villi; Cohort Studies; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Female; Heparin-binding EGF-like Growth Factor; Humans; Peptide Fragments; Placenta; Placentation; Pre-Eclampsia; Pregnancy; Protein Isoforms; Transforming Growth Factor alpha; Trophoblasts; Young Adult

We have previously reported that polymorphism in the epidermal growth factor (EGF) gene is associated with pre-eclampsia and birthweight based on case-control association studies involving two single nucleotide polymorphisms (SNP). We extended that work to investigate other SNP in the EGF gene for their association with pre-eclampsia and the weight of babies at birth.. A population-based DNA collection was genotyped to determine whether the selected SNP were polymorphic in the study population. In total, 175 women with pre-eclampsia and 171 matched normotensive controls were genotyped for the polymorphic SNP using polymerase chain reaction/restriction fragment length polymorphism and MassARRAY Sequenom iPLEX methodology.. The rs3756261A, rs4444903G, rs2237051G haplotype was associated with the highest increased risk of pre-eclampsia (odds ratio: 3.70, 95% confidence interval: 1.38-9.94; P = 0.016). The rs3756261A allele was the one that contributed to this high degree of significance. The same allele was present in the haplotype rs3756261A, rs11568943G, rs2237051G, rs11569017A, rs4698803T (likelihood ratio statistic = 20.4671, d.f. = 3, P-value = 0.0001), which was associated with the lower birthweight.. In this study we found further evidence for the association of polymorphism in the EGF gene with pre-eclampsia and the weight of babies at birth and identified rs3756261A>G as the SNP that makes the most significant contribution to this association. Bioinformatic analysis showed that this effect may be mediated by caudal type homeohox-2, a transcriptional repressor expressed in the trophoblast, for which a binding site is created at this polymorphic site when the rs3756261A allele is present.

Topics: Adolescent; Adult; Case-Control Studies; CDX2 Transcription Factor; Epidermal Growth Factor; Female; Genotype; Haplotypes; Homeodomain Proteins; Humans; Infant, Low Birth Weight; Infant, Newborn; Male; Middle Aged; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Quantitative Trait Loci

Kidney injury with proteinuria is a characteristic feature of preeclampsia, yet the nature of injury in specific regions of the nephron is incompletely understood. Our study aimed to use existing urinary biomarkers to describe the pattern of kidney injury and proteinuria in pregnancies affected by severe preeclampsia. We performed a case-control study of pregnant women from Brigham and Women's Hospital from 2012 to 2013. We matched cases of severe preeclampsia (n=25) 1:1 by parity and gestational age to 2 control groups with and without chronic hypertension. Urinary levels of kidney injury molecule-1 and complement components (C3a, C5a, and C5b-9) were measured by enzyme-linked immunosorbent assay, and other markers (albumin, β2 microglobulin, cystatin C, epithelial growth factor, neutrophil gelatinase-associated lipocalin, osteopontin, and uromodulin) were measured simultaneously with a multiplex electrochemiluminescence assay. Median values between groups were compared with the Wilcoxon signed-rank test and correlations with Spearman correlation coefficient. Analysis of urinary markers revealed higher excretion of albumin and kidney injury molecule-1 and lower excretion of neutrophil gelatinase-associated lipocalin and epithelial growth factor in severe preeclampsia compared with chronic hypertension and healthy controls. Among subjects with severe preeclampsia, urinary excretion of complement activation products correlated most closely with kidney injury molecule-1, a specific marker of proximal tubule injury (C5a: r=0.60; P=0.001; and C5b-9: r=0.75; P<0.0001). Taken together, we describe a pattern of kidney injury in severe preeclampsia that is characterized by glomerular impairment and complement-mediated inflammation and injury, possibly localized to the proximal tubule in association with kidney injury molecule-1.

Topics: Acute-Phase Proteins; Adult; Albuminuria; beta 2-Microglobulin; Biomarkers; Case-Control Studies; Complement Activation; Complement C3a; Complement C5a; Complement Membrane Attack Complex; Epidermal Growth Factor; Female; Hepatitis A Virus Cellular Receptor 1; Humans; Kidney Tubules, Proximal; Lipocalin-2; Lipocalins; Membrane Glycoproteins; Osteopontin; Pre-Eclampsia; Pregnancy; Proto-Oncogene Proteins; Receptors, Virus; Severity of Illness Index; Uromodulin

The aim of these investigations was to study three candidate genes for pre-eclampsia--epidermal growth factor (EGF), transforming growth factor alpha, and angiotensinogen--in pregnant Sinhalese women from Sri Lanka, the first such study undertaken in this ethnic group. Reproducibility of results of genetic association studies of candidate genes for pre-eclampsia has not been consistent across populations. One of the factors that may contribute to such inconsistencies is genetic stratification due to population admixture. We therefore compared the allele frequencies of these candidate genes in healthy Sri Lankan subjects from three ethnic groups--Sinhalese, Sri Lankan Tamils and Moors--and in white Western Europeans.. Allele frequencies were established in 80 subjects from each of four populations (Sinhalese, Sri Lankan Tamils, and Moors in Sri Lanka and white Western Europeans in the U.K.). A further 175 Sinhalese women with pre-eclampsia and 171 normotensive Sinhalese controls were genotyped at eight single nucleotide polymorphisms in the candidate genes.. In all genes haplotype and allele frequencies were comparable within the three Sri Lankan populations, but differed significantly from those in the white Western European population. Consequently cryptic population stratification is unlikely to have significant effects on allele or haplotype frequencies of the genes examined in this case-control study of Sinhalese women which showed a marginal association for EGF haplotypes and genotypes with pre-eclampsia (P = 0.031). This association requires replication in other populations.

Topics: Adult; Angiotensinogen; Epidermal Growth Factor; Female; Haplotypes; Humans; Polymorphism, Single Nucleotide; Pre-Eclampsia; Pregnancy; Sri Lanka; Transforming Growth Factor alpha

Normal placental development is dependent on the orchestrated differentiation of cytotrophoblast (CTB) cells. This study was aimed at studying cytotrophoblast cells from normal and preeclamptic pregnancies in a three-dimensional spheroid-based cell culture model. First trimester cytotrophoblast cells cultured as spheroids maintain their high proliferative and invasive phenotype and respond to different cytokines upon stimulation in a three-dimensional invasion assay. In contrast, third trimester cytotrophoblast spheroids maintain their quiescent nonproliferating phenotype and invasion can only be induced by EGF. Contrasting the regular spheroidal arrangement of cytotrophoblast cells from normal third trimester pregnancies, spheroidal organization of preeclamptic cytotrophoblast cells is disturbed and the cells downregulate CD105 in vivo and in vitro. Furthermore, the invasion of both normal and preeclamptic third trimester, but not first trimester cytotrophoblast cells, is inhibited by pro-inflammatory cytokines. Plasma samples from pregnant women with preeclampsia significantly stimulate the invasion of first trimester cytotrophoblast cells and the sprouting of human umbilical vein endothelial cells (HUVECs) compared to plasma samples from healthy pregnant women. Taken together, the data establish the spheroidal cytotrophoblast model as a powerful system to mimic the in vivo phenotype of first and third trimester and preeclamptic cytotrophoblast cells and demonstrate that plasma-derived factors modulate the differentiation of cytotrophoblast cells.

Topics: Angiopoietin-2; Antigens, CD; Cell Differentiation; Cell Division; Cells, Cultured; Cytokines; Down-Regulation; Epidermal Growth Factor; Female; Fibroblast Growth Factor 2; Humans; Phenotype; Placenta Growth Factor; Pre-Eclampsia; Pregnancy; Pregnancy Proteins; Pregnancy Trimester, First; Pregnancy Trimester, Third; Spheroids, Cellular; Transforming Growth Factor beta; Transforming Growth Factor beta1; Trophoblasts; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

To explore the mechanisms of adrenomedullin (ADM) regulation in normal and preeclamptic (PE) states, we determined placental production of ADM and ADM regulation by cytokines. Isolated, purified cytotrophoblast cultures from normal (n=8) and PE (n=10) placentas were cultured for 3 days in the absence or presence of 10 ng/mL epidermal growth factor (EGF), 1 ng/mL transforming growth factor (TGF)-beta1, 10 ng/mL tumor necrosis factor (TNF)-alpha, or 100 U/mL interferon (IFN)-gamma. Cells were also cultured for 3 days in 10% fetal bovine serum for determination of syncytial formation by desmoplakin staining. Pieces of normal and PE placentas were snap-frozen for ADM mRNA measurement. Results showed that basal ADM production into culture medium by radioimmunoassay was significantly lower in PE placental cells. EGF significantly stimulated ADM production in normal trophoblasts but did not in PE placentas. None of the factors TNF-alpha, TGF-beta1, or IFN-gamma altered ADM secretion in either normal or PE placentas. ADM expression by Northern blot analysis demonstrated a 34.3+/-8.3% reduction in mRNA expression in PE placentas. Syncytialization, as assessed by desmoplakin-outlined syncytial units, was decreased in PE placentas (day 3: normal, 16.7+/-1.3%; PE, 5.5+/-2.0%; P<0.01, ANOVA). However, there was a normal increment in syncytialization in response to EGF in normal and PE trophoblast preparations (EGF day 3: normal, 43.8+/-5.6%; PE, 46.1+/-12.3%). We conclude that spontaneous placental syncytialization is impaired in PE and that ADM production is markedly reduced in PE, possibly owing to an impaired EGF response. These abnormalities indicate poor placental production of ADM as the likely cause of a failed compensatory increase in maternal serum ADM levels in PE.

Topics: Adrenomedullin; Cells, Cultured; Epidermal Growth Factor; Female; Giant Cells; Humans; Peptides; Pre-Eclampsia; Pregnancy; RNA, Messenger; Trophoblasts

Pre-eclampsia is a disorder of pregnancy associated with poor extravillous cytotrophoblast invasion and above-normal rates of apoptosis in the trophoblast. Heparin-binding epidermal-growth-factor-like growth factor (HB-EGF) has strong cytoprotective activity and is an important signalling protein that regulates trophoblast invasion during early placentation. We aimed to establish whether HB-EGF expression is altered in placentae of pre-eclamptic women.. We assessed the expression of HB-EGF mRNA and protein by in-situ hybridisation and immunohistochemical techniques, respectively, in archived placental tissues from pregnancies terminated at around 20 weeks of gestation, and from women delivering between weeks 19 and 35 of gestation with preterm labour, small for gestational age infants, or pre-eclampsia.. HB-EGF mRNA and protein were expressed in villous and extravillous cytotrophoblast cells up to week 35 of gestation in placentae from women who delivered preterm. Similar levels of HB-EGF protein were found in the placentae of women who were not in labour. HB-EGF expression was reduced about five-fold (p=0.0001) in pre-eclamptic pregnancies. Fetal growth retardation, which has been linked with shallow trophoblast invasion and moderate apoptosis, was associated with placentae expressing intermediate levels of HB-EGF.. In pre-eclampsia, deficient HB-EGF signalling during placental development could impair trophoblast survival, differentiation, and invasion, leading to poor placental perfusion and hypertension.

Topics: Adult; Analysis of Variance; Epidermal Growth Factor; Female; Heparin-binding EGF-like Growth Factor; Humans; Image Processing, Computer-Assisted; Immunohistochemistry; In Situ Hybridization; Infant, Newborn; Infant, Premature; Intercellular Signaling Peptides and Proteins; Placenta; Pre-Eclampsia; Pregnancy; Pregnancy Trimester, Third; Receptors, Growth Factor; RNA, Messenger; Statistics, Nonparametric; Trophoblasts

Epidermal growth factor (EGF), an angiogenic and mitogenic peptide, is known to be essential for normal fetal development in mice. Hypothetically, low maternal urine EGF levels might be associated with intrauterine growth restriction (IUGR) or pre-eclampsia (PE). We carried out a prospective study of 1009 consecutive women whose urine was sampled in early pregnancy (at a median of 13 weeks of gestation) between January and November 1993. Thirty women gave birth to IUGR babies and 24 developed PE. The study was designed as a nested case-control study with two matched controls for each case. EGF and human chorionic gonadotrophin (HCG) levels were measured and expressed in ng EGF/mg creatinine and IU HCG/mg creatinine. Logistic regression analysis was made with EGF or HCG levels as explanatory variables. Urinary EGF levels were significantly lower in the IUGR subgroup than in their controls, but no such difference was found between the PE subgroup and their controls. In the series as a whole, smokers were found to have lower EGF and HCG levels than non-smokers. In addition, correlation was found to exist between EGF and HCG levels (Spearman's rho 0.35; P<0.001). We conclude that a relative deficiency of EGF in early pregnancy might be one of the pathophysiological mechanisms of IUGR. However, the EGF level was an insufficiently discriminative variable to be of use for screening purposes.

Topics: Adult; Case-Control Studies; Chorionic Gonadotropin; Epidermal Growth Factor; Female; Fetal Growth Retardation; Humans; Logistic Models; Pre-Eclampsia; Pregnancy; Prospective Studies

Placental pathology in preeclampsia (PE) and intrauterine growth retardation (IUGR) is associated with alterations of the placental epidermal growth factor receptor (EGFR). It is encoded by a single gene, which gives rise to two different full-length transcripts and one putative truncated transcript in the placenta. The aim was to investigate if the placental mRNA expression pattern of EGFR differs between women with PE and/or IUGR and normal pregnancies. Tissue samples from placentas were obtained immediately after delivery. Total nucleic acids were prepared and mRNA levels of EGFR transcripts were measured by a solution hybridization technique. In the group with IUGR the placental mRNA expression of the two full-length transcripts was found to be significantly lower than in placentas from normal pregnancy, whereas the expression of the truncated transcript was higher. The groups with PE or PE with IUGR had a significantly higher mRNA expression of the truncated transcript, while there were no significant differences in the mRNA expression of the two full-length transcripts. These findings are consistent with an important role for EGFR in the regulation of placental and fetal growth.

Topics: Biopsy; Epidermal Growth Factor; Female; Fetal Growth Retardation; Gene Expression Regulation, Developmental; Gestational Age; Humans; Nucleic Acid Hybridization; Placenta; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; RNA Probes; RNA, Messenger; Scintillation Counting