Showing papers by "Roberto Romero published in 2006"

Soluble endoglin contributes to the pathogenesis of preeclampsia.

Abstract: Preeclampsia is a pregnancy-specific hypertensive syndrome that causes substantial maternal and fetal morbidity and mortality. Maternal endothelial dysfunction mediated by excess placenta-derived soluble VEGF receptor 1 (sVEGFR1 or sFlt1) is emerging as a prominent component in disease pathogenesis. We report a novel placenta-derived soluble TGF-beta coreceptor, endoglin (sEng), which is elevated in the sera of preeclamptic individuals, correlates with disease severity and falls after delivery. sEng inhibits formation of capillary tubes in vitro and induces vascular permeability and hypertension in vivo. Its effects in pregnant rats are amplified by coadministration of sFlt1, leading to severe preeclampsia including the HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome and restriction of fetal growth. sEng impairs binding of TGF-beta1 to its receptors and downstream signaling including effects on activation of eNOS and vasodilation, suggesting that sEng leads to dysregulated TGF-beta signaling in the vasculature. Our results suggest that sEng may act in concert with sFlt1 to induce severe preeclampsia.

Soluble endoglin and other circulating antiangiogenic factors in preeclampsia.

Abstract: Background Alterations in circulating soluble fms-like tyrosine kinase 1 (sFlt1), an antiangiogenic protein, and placental growth factor (PlGF), a proangiogenic protein, appear to be involved in th...

Inflammation in preterm and term labour and delivery.

Abstract: Inflammation has been implicated in the mechanisms responsible for preterm and term parturition, as well as fetal injury. Out of all of the suspected causes of preterm labour and delivery, infection and/or inflammation is the only pathological process for which both a firm causal link with preterm birth has been established and a molecular pathophysiology defined. Inflammation has also been implicated in the mechanism of spontaneous parturition at term. Most cases of histopathological inflammation and histological chorioamnionitis, both in preterm and term labour, are sub-clinical in nature. The isolation of bacteria in the amniotic fluid, known as microbial invasion of the amniotic cavity, is a pathological finding; the frequency of which is dependent upon the clinical presentation and gestational age. There is a window of time during which it may be possible to detect a 'molecular signature of inflammation' by analysis of the transcriptome before histological evidence is observed. This article reviews the role of inflammation in preterm and term parturition. It is possible that modulation of inflammation using anti-inflammatory cytokines, corticoids, antioxidants and/or other factors may complement antibiotic therapy and limit fetal injury.

Evolution of the mammalian placenta revealed by phylogenetic analysis

Abstract: The placenta is essential for the success of therian mammalian reproduction. Intense selective pressure has shaped changes in placental anatomy and function during mammalian cladogenesis. Here we challenge the view that the hemochorial placenta is a derived feature in haplorhine primates. Using phylogenetic and statistical analyses of molecular and morphological data, we demonstrate that the ancestral eutherian mammalian placenta had the distinctive features of (i) hemochorial placental interface, (ii) a discoid shape, and (iii) a labyrinthine maternofetal interdigitation. These results reveal that the first eutherians had a deeply invasive placenta and imply that the major role of the placenta in sustaining pregnancy and promoting gestational development existed throughout the eutherian lineage that descended to humans from the last common ancestor of placental mammals. The ancestral state reconstructions demonstrate both clade-specific patterns of placentation and specific cases of convergent evolution within individual eutherian clades. Determining the mammalian pattern of change in placental morphology is important for understanding the evolutionary pressures faced by these lineages. The effects of selection pressures on the efficiency of placentation may stem from changes in nutritional demand, gestational length, number of embryos per pregnancy, uterine shape, and maternal body constitution. The influence of these factors on placental development needs further investigation.

A sonographic short cervix as the only clinical manifestation of intra-amniotic infection.

Abstract: OBJECTIVE— A sonographically short cervix is a powerful predictor of spontaneous preterm delivery. However, the etiology and optimal management of a patient with a short cervix in the midtrimester of pregnancy remain uncertain. Microbial invasion of the amniotic cavity (MIAC) and intraamniotic inflammation are frequently present in patients with spontaneous preterm labor or acute cervical insufficiency. This study was conducted to determine the rate of MIAC and intra-amniotic inflammation in patients with a cervical length <25 mm in the mid-trimester. STUDY DESIGN—A retrospective cohort study was conducted of patients referred to our high risk clinic because of a sonographic short cervix or a history of a previous preterm birth. Amniocenteses were performed for the evaluation of MIAC and for karyotype analysis in patients with a short cervix. Fluid was cultured for aerobic and anaerobic bacteria, as well as genital mycoplasmas. Patients with MIAC were treated with antibiotics selected by their physician. RESULTS—Of 152 patients with a short cervix at 14–24 weeks, 57 had amniotic fluid analysis. The prevalence of MIAC was 9% (5/57). Among these patients, the rate of preterm delivery (<32 weeks) was 40% (2/5). Microorganisms isolated from amniotic fluid included Ureaplasma urealyticum (n=4) and Fusobacterium nucleatum (n=1). Patients with a positive culture for Ureaplasma urealyticum received intravenous Azithromycin. Three patients with Ureaplasma urealyticum had a sterile amniotic fluid culture after treatment, and subsequently delivered at term. The patient with Fusobacterium nucleatum developed clinical chorioamnionitis and was induced. CONCLUSION—1) Sub-clinical MIAC was detected in 9% of patients with a sonographically short cervix (<25 mm); and 2) maternal parenteral treatment with antibiotics can eradicate MIAC caused by Ureaplasma urealyticum. This was associated with delivery at term in the three patients whose successful treatment was documented by microbiologic studies.

Normal and abnormal transformation of the spiral arteries during pregnancy.

Abstract: This article reviews the anatomy and physiology of the uterine circulation, with emphasis on the remodeling of spiral arteries during normal pregnancy, and the timing and anatomical pathways of trophoblast invasion of the spiral arteries. We review the definitions of the placental bed and basal plate of the placenta, their relevance to the study of the physiologic transformation of the spiral arteries, as well as the methods to obtain and examine placental bed biopsy specimens. We also examine the role of the extravillous trophoblast in normal and abnormal pregnancies, and the criteria used to diagnose failure of physiologic transformation of the spiral arteries. Finally, we comment on the use of uterine artery Doppler velocimetry as a surrogate marker of chronic uteroplacental ischemia.

Expression and secretion of antiviral factors by trophoblast cells following stimulation by the TLR-3 agonist, Poly(I : C)

Abstract: BACKGROUND During pregnancy, the placenta may become exposed to micro-organisms, such as viruses, which may pose a substantial threat to the embryo/fetus well-being. Recent insight into the immunological capabilities of the trophoblast suggests that the placenta may function as an active barrier by recognizing and responding to pathogens through Toll-like receptors (TLRs). METHODS The objective of this study was to determine whether the engagement of TLR-3 with viral dsRNA by first-trimester trophoblast could induce the production of factors necessary to generate an antiviral response. Therefore, trophoblast cells were exposed to the TLR-3 agonist, Poly(I : C). RESULTS We report that following stimulation with Poly(I : C), first-trimester trophoblast cells produce interferon beta (IFNbeta) and secretory leukocyte protease inhibitor (SLPI), as well as the intracellular factors 2',5'-oligoadenylate synthetase (OAS), Myxovirus-resistance A (MxA) and apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (APOBEC3G). This response is TLR-3 specific because the TLR-4 ligand, lipopolysaccharide (LPS), had no effect on the production of these antimicrobial factors. Furthermore, we describe a positive feedback mechanism in which IFNbeta enhances the antiviral response by promoting the production of OAS, MxA and APOBEC3G. CONCLUSIONS These findings suggest that trophoblast cells are able to recognize and specifically respond to viral products in a highly regulated fashion and that the placenta may be pivotal in the control of viral infections at the maternal-fetal interface.

Examination of the fetal heart by four-dimensional (4D) ultrasound with spatio-temporal image correlation (STIC).

Abstract: Three-dimensional (3D) and four-dimensional (4D) ultrasound have been proposed to be valuable tools for the examination of the fetal heart1–52. The ultimate goal of 3D and 4D ultrasound is to improve the detection rates of congenital heart disease53–63 by decreasing the dependency on operator skills required by twodimensional (2D) ultrasound64,65. This is important since congenital heart disease is the leading cause of death among infants with congenital anomalies66, and prenatal diagnosis is associated with decreased neonatal morbidity and mortality rates67–70. Several techniques for prenatal examination of the fetal heart by 3D/4D ultrasound have been proposed using a variety of technologies, including free-hand 3D ultrasound with and without position sensors1,3,7–9,12,30, 3D ultrasound with automated mechanical acquisition4,5,7,16,26, 4D ultrasound with a variety of gating algorithms (temporal Fourier analysis of heart motion3, M-Mode1, Doppler11,17–19,39,49, spatio-temporal image correlation (STIC)27,28,34), as well as real-time 4D ultrasound with 2D matrix-array transducers10,15,24,31,46,52. In this article, we describe a practical approach for the examination of the fetal heart using 4D ultrasound with STIC.

Evidence for interleukin-10-mediated inhibition of cyclo- oxygenase-2 expression and prostaglandin production in preterm human placenta.

Abstract: Problem Interleukin-10 (IL-10) is thought to be a key cytokine for the maintenance of pregnancy. Here we examined the expression profiles of IL-10 and cyclo-oxygenase-2 (COX-2), and the effect of IL-10 on COX-2 expression and prostaglandin release in the human placenta from preterm labor deliveries associated with chorioamnionitis. Method of study Placental tissues from preterm labor and term labor deliveries were processed for ex vivo placental explant culture system. IL-10 expression was assessed by enzyme-linked immunosorbent assay (ELISA) and immunohistochemical (IHC) analysis. COX-2 expression was evaluated by IHC, Western blotting and reverse transcriptase-polymerase chain reaction. Prostaglandin E2 (PGE2) release was measured by ELISA. Results IL-10 was significantly reduced in chorioamnionitis-associated preterm labor as well as in term labor placental tissues compared with second trimester normal pregnancy samples obtained from elective terminations. Similar results were obtained with freshly isolated cytotrophoblasts from these deliveries. As expected, COX-2 mRNA was detected at significant levels in tissues from term and preterm labor deliveries compared with no labor term deliveries. Importantly, IL-10 inhibited COX-2 expression in cultured placental explants from preterm labor deliveries, but not from term labor samples. Inhibition of COX-2 expression coincided with reduced PGE2 release. Conclusion These results demonstrate the importance of IL-10 in countering inflammation associated with preterm labor, and suggest that term and preterm parturition may, in part, represent different conditions.

A role of the anti-angiogenic factor sVEGFR-1 in the 'mirror syndrome' (Ballantyne's syndrome).

Abstract: Background. ‘Mirror syndrome’ (Ballantyne's syndrome) refers to the association of fetal hydrops with placentomegaly and severe maternal edema. Preeclampsia occurs in approximately 50% of these cases. Soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), an anti-angiogenic factor, has been implicated in the pathophysiology of preeclampsia (PE).Objective. The objective of this study was to determine if the maternal plasma concentration of sVEGFR-1 is elevated in patients with mirror syndrome.Study design. This case-control study included patients with uncomplicated pregnancies (n = 40) and those with mirror syndrome (n = 4) matched for gestational age. Mirror syndrome was defined as fetal hydrops and severe maternal edema. Maternal plasma sVEGFR-1 concentrations were determined using specific enzyme-linked immunosorbent assays. Immunohistochemistry of sVEGFR-1 on villous trophoblasts was also performed in samples from one patient with mirror syndrome and compared with those from a patient with ...

A functional SNP in the promoter of the SERPINH1 gene increases risk of preterm premature rupture of membranes in African Americans

Abstract: Prematurity is more prevalent in African Americans than in European Americans. We investigated the contribution of a functional SNP in the promoter of the SERPINH1 gene, enriched among those of African ancestry, to preterm premature rupture of membranes (PPROM), the leading identifiable cause of preterm birth. SERPINH1 encodes heat-shock protein 47, a chaperone essential for collagen synthesis. The SERPINH1 656 minor T allele had a greater frequency in African populations and African Americans than in European Americans (12.4% vs. 4.1%). The 656 T allele displayed significantly reduced promoter activity compared to the major 656 C allele in amnion fibroblasts, which lay down the fibrillar collagen that gives tensile strength to the amnion. An initial case-control study demonstrated that the 656 T allele is significantly more frequent in African-American neonates (P < 0.0009) born from pregnancies complicated by PPROM compared with controls (odds ratio of 3.22, 95% confidence interval 1.50, 7.22). There was no significant difference in ancestry among cases and controls using a dihybrid model based on 29 ancestry-informative markers. Adjusting the results of the case-control study for admixture still yielded a statistically significant association between the 656 T allele and PPROM (P < 0.002). A follow-up case-control study gave similar results. The combined case-control findings showed a highly significant (P < 0.0000045) association between the 656 T allele and PPROM. The SERPINH1 656 T allele is the first example of an ancestry-informative marker associated with preterm birth in African Americans.

Dermatitis as a component of the fetal inflammatory response syndrome is associated with activation of Toll-like receptors in epidermal keratinocytes.

Abstract: Aims Microbial invasion of the amniotic cavity (MIAC) elicits a fetal inflammatory response such as funisitis and chorionic vasculitis. However, little is known about the changes of fetal skin during MIAC. Toll-like receptors recognize microbial products and initiate an immune response. The aims of this study were to examine histopathological features of fetal skin exposed to MIAC and to assess the changes in Toll-like receptor (TLR)-2 and TLR-4 expression. Methods and results Skin samples were obtained from fetal autopsies (n = 12). The cases were classified according to the presence (n = 8) or absence (n = 4) of acute chorioamnionitis and analysed by immunohistochemistry using a panel of antibodies. Leucocytic infiltrates into the superficial dermis were observed in cases with chorioamnionitis; the majority of inflammatory cells were neutrophils, lymphocytes and histiocytes. TLR-2 immunoreactivity in the skin was stronger in fetuses with chorioamnionitis than in those without this condition. However, immunoreactivity of TLR-4 in the fetal skin was constitutively expressed, regardless of the presence or absence of chorioamnionitis. Conclusions This study demonstrates for the first time that fetal dermatitis can be detected and is part of the fetal inflammatory response syndrome (FIRS). We propose that this ‘FIRS-associated fetal dermatitis’ is a fetal counterpart of chorioamnionitis.

Funisitis in term pregnancy is associated with microbial invasion of the amniotic cavity and intra-amniotic inflammation.

Abstract: Objective. Funisitis is the histologic counterpart of the fetal inflammatory response syndrome, which is a multisystemic disorder associated with impending preterm delivery and adverse neonatal outcome. The purpose of this study was to examine the relationship between funisitis and the microbiologic status of amniotic fluid (AF) and AF white blood cell (WBC) count in patients at term.Methods. The relationship between the presence of funisitis, AF culture, and AF WBC count was examined in 832 consecutive patients who delivered a term neonate within 72 hours of amniocentesis. AF was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Funisitis was diagnosed in the presence of neutrophil infiltration into the umbilical vessel walls or Wharton's jelly. AF WBC count was analyzed in a hemocytometer chamber. Nonparametric statistics were used for data analysis.Results. Funisitis was present in 4% (30/832) of cases. A positive AF culture was more common in cases with funisitis than in those w...

A novel algorithm for comprehensive fetal echocardiography using 4-dimensional ultrasonography and tomographic imaging.

Abstract: Objective Tomographic ultrasound imaging (TUI) is a new display modality that allows simultaneous visualization of up to eight parallel anatomical planes. This study was designed to determine the role of a novel algorithm combining spatiotemporal image correlation (STIC) and TUI to visualize standard fetal echocardiography planes.

Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor

Abstract: Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is down regulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O(2) ( approximately 2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O(2) upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O(2), signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O(2) and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O(2) rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts.

Four-dimensional ultrasonography of the fetal heart using a novel Tomographic Ultrasound Imaging display

Abstract: Objective: The objective of this study was to investigate the feasibility of examining the fetal heart with Tomogra- phic Ultrasound Imaging (TUI) using four-dimensional (4D) volume datasets acquired with spatiotemporal image correlation (STIC). Material and methods: One hundred and ninety-five fetuses underwent 4D ultrasonography (US) of the fetal heart with STIC. Volume datasets were acquired with B-mode (ns195) and color Doppler imaging (CDI) (ns168), and were reviewed offline using TUI, a new dis- play modality that automatically slices 3D/4D volume datasets, providing simultaneous visualization of up to eight parallel planes in a single screen. Visualization rates for standard transverse planes used to examine the fetal heart were calculated and compared for volumes acquired with B-mode or CDI. Diagnoses by TUI were compared to postnatal diagnoses. Results: (1) The four- and five-chamber views and the three-vessel and trachea view were visualized in 97.4% (190/195), 88.2% (172/195), and 79.5% (142/195), respectively, of the volume datasets acquired with B- mode; (2) these views were visualized in 98.2% (165/ 168), 97.0% (163/168), and 83.6% (145/168), respectively, of the volume datasets acquired with CDI; (3) CDI contributed additional diagnostic information to 12.5% (21/168), 14.2% (24/168) and 10.1% (17/168) of

What does 2-dimensional imaging add to 3- and 4-dimensional obstetric ultrasonography?

Abstract: Objective The objective of this study was to determine if two-dimensional ultrasound adds diagnostic information to that provided by the examination of three-dimensional/four-dimensional (3D/4D) volume datasets alone.

Gestational age-dependent up-regulation of prostaglandin D synthase (PGDS) and production of PGDS-derived antiinflammatory prostaglandins in human placenta

Abstract: Context: The importance of prostaglandin (PG) signaling pathways to the maintenance of pregnancy and initiation of labor is well recognized. However, the complexity of these pathways and the mechanism(s) of their coordinated regulation in physiological and pathological conditions are only now being appreciated. Objectives: In this report we provide new evidence of a complete pathway for the biosynthesis and actions of PGD2 and its metabolites within human gestational tissues. Materials and Methods: Using immunohistochemistry and Northern and Western blotting, we demonstrate the dynamic regulation of H-type PGD synthase (PGDS) in placenta during gestation; in contrast, L-type PGDS and its PG products were detected in amniotic fluid, with increased amounts associated with labor. Results: Placental tissues were shown to express both forms of the PGD2 receptor identified to date, D prostanoid1 (DP1) and DP2/chemotactic receptor on type 2 helper T cells, with a distribution consistent with the villous placenta...

Applications of 2-dimensional matrix array for 3- and 4-dimensional examination of the fetus: a pictorial essay.

Abstract: OBJECTIVES Two-dimensional (2D) matrix array is a new technology for the performance of 3-dimensional and 4-dimensional (4D) ultrasonography. In this study, we report the use of a 2D matrix array transducer for examination of fetal structures including the fetal heart. METHODS Thirty-four fetuses without abnormalities and 19 fetuses with congenital anomalies were examined with a 2D matrix array transducer (x3-1, IE-33; Philips Medical Systems, Bothell, WA). Median gestational age was 25 6/7 weeks (range, 13 0/7-40 1/7 weeks). RESULTS (1) A 360 degrees rotation and examination of selected structures was possible in the second trimester. (2) Structures were examined by maintaining the transducer in a fixed position and rotating the volume using the system trackball. (3) Dorsal and ventral parts of the hands and feet were visualized in a single volume data set, in real time, without moving the transducer. (4) Real-time en face visualization of atrioventricular valves was possible from the ventricular or atrial chambers. (5) Four-dimensional images of bones were obtained by decreasing gain settings only, with no need for cropping. (6) Four-dimensional reconstruction of vascular structures was possible with color Doppler imaging. Two limitations were identified: (1) lower resolution than mechanical volumetric transducers, and (2) narrow volume display. CONCLUSIONS Real-time direct 4D imaging with 360 degrees rotation for examination of fetal anatomic structures is feasible. This technology allows examination of fetal structures from multiple perspectives, in real time, without the need to move the transducer in the maternal abdomen. Further technological developments may overcome the limitations identified in this study.