Placenta

We evaluated the role of placental protein 13 (PP13; galectin 13) in the process of trophoblast invasion and decidual necrosis. Immunohistochemical analysis for PP13, immune cells, human placental lactogen, cytokeratin, and apoptosis markers was performed on 20 elective pregnancy termination specimens between 6 and 15 weeks of gestation. Placental protein 13 was localized to syncytiotrophoblasts in the chorionic villi and to occasional multinucleated luminal trophoblasts within converted decidual spiral arterioles. Cytotrophoblasts, anchoring trophoblasts, and invasive trophoblasts did not stain for PP13. Extracellular PP13 aggregates were found around decidual veins associated with T-cell-, neutrophil-and macrophage-containing decidual zones of necrosis (ZONEs). We hypothesize that PP13 is secreted into the intervillus space, drains through the decidua basalis veins, and forms perivenous PP13 aggregates which attract and activate maternal immune cells. Thus, syncytiotrophoblast-derived PP13 may create a ZONE that facilitates trophoblast invasion and conversion of the maternal spiral arterioles.

The instillation of surfactant into the airways of patients with respiratory distress syndrome (RDS), especially in the neonatal period, is a proven therapy. The preventive therapy of RDS through intra-amniotic injection of surfactant has been reported recently. It has not been conclusively shown, however, that the surfactant administered in this way actually reaches the fetal pulmonary airways. To study the distribution in fetal organs of a natural surfactant labeled with technetium-99m and injected through amniocentesis into the amniotic sac of guinea pigs in the last third of pregnancy. After stimulating fetal respiratory movements with aminophylline 0.3 ml of an aqueous suspension containing 0.75 mg of phospholipids of a natural bovine surfactant labeled with technetium-99m, together with 0.1 ml of the biological dye carmine indigo, were injected into the amniotic sac. One hour later fetuses were delivered by cesarean section. In those that were dye-stained, dosimetric and gammagraphic tests were applied to trachea, lungs, esophagus, stomach, heart, liver, kidneys and placenta. Significant radio isotopic activity was found in both lungs of six treated fetuses, with a dose capture of between 1.0% and 5.3% of total dose. The level of activity in the stomachs was similar to that in the lungs (0.9% to 3.0% dose capture), whereas activity in other organs was negligible except in two placentae. No radio isotopic activity was found in non-injected control fetuses. In the present animal model natural surfactant injected intra-amniotically is aspirated into the lungs within one hour.

We have carried out a DNA binding site screen of a 32-week human placental cDNA library using a consensus homeodomain binding site as a probe. This study represents the first library screen carried out to isolate homeobox genes from the human placenta. We have shown that three homeobox genes known to be expressed in the embryo, HB24, GAX and MSX2 are also expressed in the placenta. We have also identified a novel homeobox gene, DLX4, that shows 85% sequence identity with the homeodomain encoded by the Drosophila Distal-less (Dll ) gene. DLX4 therefore represents a new member of the Distal-less family of homeobox genes. This is the first evidence that members of the Distal-less family of homeobox genes are expressed in the placenta. Using fluorescence in situ hybridisation (FISH ), DLX4 has been assigned to human chromosome 17q21-q22. This places DLX4 in the same region of chromosome 17 as another member of the Distal-less family, DLX3 , and the HOX-B homeobox gene cluster (Acampora et al., 1989;. Members of the Distal-less family (DLX1 and DLX2; DLX5 and DLX6) are found as closely linked pairs on human chromosomes . We predict that DLX3 and DLX4 are closely linked and have arisen through gene duplication and divergence from a common ancestral precursor.

To evaluate the accuracy of sonographic classification of chorionicity in a large cohort of twins and investigate which factors may be associated with sonographic accuracy. We conducted a secondary analysis of a randomized trial of preterm birth prevention in twins. Sonographic classification of chorionicity was compared with pathologic examination of the placenta. Maternal (age, body mass index, diabetes, and hypertension), obstetric (prior cesarean delivery, gestational age at the first sonographic examination, and antepartum bleeding), and sonographic (oligohydramnios, polyhydramnios, and twin-twin transfusion syndrome) factors were assessed for their possible association with accuracy. A total of 545 twin sets in which chorionicity was classified by sonography before 20 weeks' gestation were included; 455 were dichorionic and 90 were monochorionic based on pathologic examination. Sonography misclassified 35 of 545 twin pregnancies (6.4%): 18 of 455 dichorionic twins (4.0%) a...

Somatic nuclear transfer (NT) in cattle is often accompanied by severe placental anomalies, hypertrophy, and hydrallantois, which induce a high rate of pregnancy losses throughout gestation. These placental deficits are associated with an abnormal increase of the maternal plasma levels of pregnancy-associated glycoprotein (PAG), produced by the trophoblastic binucleate cells (BNC) of the placenta. The objective of this study was to analyze the origin of the abnormally elevated PAG concentrations in the peripheral circulation of NT recipients during pathological pregnancies. Concentrations of PAG were measured both in maternal blood, in chorionic and cotyledonary tissular extracts from control recipients (after artificial insemination, AI, or in vitro fertilization, IVF) and clone recipients on Day 32, Day 62, and during the third trimester of gestation. Three different radioimmunoassay (RIA) systems were used. One homologous RIA for PSP60, similar to bovine PAG-1 (PAG 67kDa ), and two heterologous RIA with PAG 67kDa as standard and tracer, and antisera anti-caprine PAG (AS#706 and AS#708). Circulating and tissular concentrations of bovine placental lactogen (bPL), a glycoprotein also produced by BNC, were determined by RIA at the same stages. The number of BNC in the placental tissues was determined by cell counting after immunostaining with anti PSP60 antibody on tissue sections from control and NT pregnancies. Maternal plasma PAG concentrations were not different among groups on Day 32, but they were significantly higher in NT than in control pregnancies on Day 62 with all three RIA and during the third trimester with two RIA (RIA-PSP60 and RIA with AS#708). Circulating bPL concentrations were undetectable on Days 32 and 62 and were not different in the third trimester between NT and control pregnancies. Tissular amounts of PAG on total proteins were not different between the two groups at all stages studied. No difference was determined in the percentage of PSP60-positive BNC in placental tissues between controls and NT on Day 62 and during the third trimester of pregnancy. Western blots of tissular extracts from placenta showed no major molecular weight changes of PAG in NT pregnancies compared to controls. No differences in maternal circulation concentrations or tissular content of bPL were observed between control and NT pregnancies. In conclusion, the specific increase of PAG in maternal plasma concentrations during abnormal NT pregnancies do not result from a higher proportion of BNC, or an increased protein expression of PAG and could be due to changes in the composition of terminal glycosylation which result into a clearance decrease of PAG from the circulation.