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PubMed2004

Complex patterns of GCM1 mRNA and protein in villous and extravillous trophoblast cells of the human placenta.

The Gcm1 gene encodes a transcription factor that is essential for both syncytiotrophoblast differentiation and formation of chorionic villi in mice. Its early expression is very unusual in that it defines a subset of trophoblast cells in the chorion, a layer that otherwise contains trophoblast stem cells. While Gcm1 mRNA expression initiates independently within the chorion, the subsequent maintenance of mRNA expression as well as the onset of protein accumulation is dependent on contact with allantoic mesoderm. Previous studies have shown that human GCM1 mRNA and protein are detectable in the placenta, but their patterns have not been compared nor precisely localized. We, therefore, conducted the present study to determine if the human mRNA and protein are subject to the same complexities of regulation as the mouse. In situ hybridization studies showed that the GCM1 mRNA was expressed in villous cytotrophoblast cells, but only a subset and never within cells immediately at the base of columns. Interestingly, the mRNA was detected throughout the cytotrophoblast columns. GCM1 protein expression studies demonstrated that the transcription factor was present mainly within the nuclei of a subset of cytotrophoblast cells, consistent with its role as a transcription factor. Feint cytoplasmic staining of the transcription factor was found in the syncytiotrophoblast but not in aggregated syncytial nuclei. Nuclear immuno-reactivity for the GCM1 protein was detected in occasional nuclei in the distal part of the column. Therefore, GCM1 expression is regulated both at the transcriptional and translational level. Overall, these studies show that the general features of GCM1 mRNA and protein expression in the human placenta are conserved with the mouse. They also highlight the fact that villous cytotrophoblast cells are extremely heterogeneous with respect to GCM1 expression, a factor that should be considered when using isolated cytotrophoblast cells for culture studies.

Blotting, Northern↗
PubMed1979

Demonstration of immunoreactive somatostatin-like substance in villi and decidua in early pregnancy.

With the use of the radioimmunoassay for growth hormone--releasing inhibiting factor (GIF), it was found that measurable amounts of GIF-like substance existed in the chorionic villi and decidua of pregnant women. The indirect immunofluorescent method revealed that the higher intensity of GIF-like immunofluorescence was presented in cytotrophoblasts rather than in syncytiotrophoblasts of the villi and in stromal cells of the decidua.

Antigens↗
PubMed1981

Ultrastructure of the nidatory site in tubal pregnancy.

Nidatory site of pre-abortive tubal pregnancy, obtained from 41 years old women was studied in both scanning and transmission electron microścopes. The nidatory site was basically composed of anchoring villi, trophoblastic column and shell, fibrinoid layer and marked round cell infiltration. In spite of the histologically normal appearance of the chorionic villi, villous syncytiotrophoblast ultrastructurally showed slight tendency of degeneration, being concurrent with blighted ovum. The trophoblast at the trophoblastic column and shell contained a great amount of glycogen which decreased at the distal part near and in the fibrinoid layer. The degenerating trophoblast were surrounded by massive fibrin bundles and fibrin bundles and fibrin-like deposits. The more the degeneration of the trophoblast proceeded, the more the fibrin deposits accumulated around the trophoblast. The trophoblast which ran over the fibrinoid layer was scarcely observed and if there, it showed marked degenerative appearance. These findings suggest the possible role of fibrinoid layer: protection of maternal tissue from trophoblastic invasion, not the protection of fetus from maternal immunological attack. No direct contact such as tight junction, desmosome and so on between trophoblast and maternal cell was observed in the present study, suggesting the formation of special connection with the allogeneic cell, one of the unique characters of the trophoblast, is expressed only when it is primitive in the early stage of development.

Adult↗
PubMed1992

Trisomy 16 confined to the placenta.

Two cases with trisomy 16 confined to the placenta are presented. Prenatal diagnosis was indicated because of fetal growth retardation. In case 1, a phenotypically normal but small-for-date boy was born. In case 2, the fetus turned out to be triploid on cordocentesis. In both instances the trisomy 16 was recovered from the placenta. Recovery indicates that the abnormality was present in the placenta during the time of fetal growth retardation, which supports an aetiological relationship. Strict appliance of the current models cannot readily explain the observed discrepancies. In case 2, a chimeric placenta as a result of a vanishing twin is assumed. Cases of placental trisomy 16 published after 1988 are reviewed. It is concluded that confined placental trisomy 16 can cause intrauterine growth retardation if present in both the direct preparation and the villus culture. The chances of finding a chromosomally abnormal fetus (mosaic trisomy 16, triploidy) after diagnosis of trisomy 16 in chorionic villi are low but warrant further investigations.

Adult↗
PubMed1992

The "twin peak" sign: reliable evidence of dichorionic twinning.

In twin pregnancies with a single placental zone, the presence of a triangular projection of placental tissue beyond the chorionic surface, extending between the layers of the intertwin membrane, has provided reliable evidence that there are two fused placentas (dichorionic, diamniotic) rather than a single shared placenta (monochorionic, diamniotic). This observation, dubbed the "twin peak" sign, was identified in 15 twin pregnancies, all proven to be dichorionic at birth, and in five triplet pregnancies, all proven to be trichorionic. This finding is produced by proliferating chorionic villi growing into the potential space between the two layers of chorion in the intertwin membrane. The single chorion of a monoplacental twin pregnancy serves as an intact barrier, preventing villi from growing between the two amniotic layers. A decision sequence incorporating the use of the twin peak sign is described for determining the type of twinning that has occurred.

Chorion↗
PubMed1988

[An ultrastructural study of capillary endothelial cells in toxemic placental villi using a quick quenching method].

The pathophysiological phenomena of placental microcirculation in cases of toxemia of pregnancy were studied. Fetal capillary endothelial cells, which were constituents of placental barrier, in chorionic villi from 5 normal and 10 toxemic pregnancies were ultrastructurally observed. The small pieces of tissue were prepared by a quick quenching & freeze substitution method, immediately after removal or after incubation in catecholamine solution. 1) In normal placentae, the thickness of the endothelial cells was uniform, and so was the distribution of cytoplasmic organelles. After incubation in catecholamine solution, endothelial cytoplasm partly protruded towards the capillary lumen, forming humps, which contained plenty of 6 nm diameter filaments which were thought to be actin filaments. 2) In toxemic placentae, 10nm diameter filaments increase to form bundles in endothelial cytoplasm. No cytoplasmic organelles were found here. Especially in placentae from severe toxemic pregnancies with IUGR, the augmentation of these filaments was so pronounced that the capillaries seemed as if they were solid molds, and it is possible that the blood flow is disturbed in these capillaries. 3) The endothelial cells occupied by bundles of filaments contained almost no organelles or pinocytotic vesicles. This fact suggests that the quantity of filaments affects the ability to actively transport the substances of mother and fetus.

Chorionic Villi↗
PubMed1995

Identification and isolation of corticotrophin-releasing hormone-positive cells from the human placenta.

During human pregnancy, plasma corticotrophin-releasing hormone (CRH) levels rise from undetectable amounts prior to 20 weeks gestation to reach a peak near term, with an exponential rise during the final 5 weeks of gestation. Within hours of parturition plasma levels fall and rapidly return to undetectable baseline measurements. The appearance of CRH in maternal plasma has been attributed to the placental production and subsequent release into the maternal circulation of this hormone. Previous studies have shown that human placental extracts contain a CRH-like peptide and this has been reinforced by the observation of CRH mRNA in placental tissue. Initial attempts to identify the site of production using immunocytochemistry have led to conflicting results. This study attempts to clarify this situation by using a variety of highly specific anti-CRH antibodies to show the cellular expression of placental CRH. Intense CRH staining was observed in the syncytial trophoblast layer in first trimester and term chorionic villi, whilst the underlying cytotrophoblast appeared to be negative. The fetal membranes also contained CRH immunoreactivity with the cytotrophoblast cells in the chorionic membrane displaying the most intense staining. CRH immunoactivity was also observed in the amnion and in some cells in the decidua. As a model of cellular CRH expression, cytotrophoblast cells from term chorionic membrane were isolated and shown to be positive for CRH.

Chorionic Villi↗
PubMed1987

Primary hepatic pregnancy.

A case of primary hepatic pregnancy in a 31-year-old woman is reported. She underwent laparotomy due to abdominal symptoms suggesting peritonitis. A 2 x 2 cm large bleeding lesion was found on the upper side of the right lobe of the liver. Microscopic examination of the excised lesion showed chorionic villi and trophoblast cells. The patient made an uneventful recovery.

Adult↗
PubMed1982

Developmental changes in rhesus monkey placental villi and cell columns. Scanning electron microscopy.

Developing rhesus monkey placentas were analyzed by scanning electron microscopy with special attention directed toward defining stages in the development of the villus branches. The initial phase in formation of villi was the conversion of reticulated trabeculae of syncytial trophoblast into chorionic villi by growth and proliferation of cell columns of cytotrophoblast. These villi were stout and unbranched. The second phase of development appeared to be the longitudinal splitting of the villi and cell columns to form groups of parallel branches but there was a common insertion of these into the basal plate. The third phase in formation of villi, which appeared to begin at about the same time as the longitudinal splitting occurred, was the outgrowth of large-diameter side branches in a zone nearer the chorionic plate. At about 38-40 days of gestation the next stage in villus formation occurred, characterized by the emergence of numerous, small syncytial sprouts. Continued proliferation of villi at later stages of gestation resulted in a decreased diameter of the terminal villi and an increasing complexity in the course of fetal capillaries.

Animals↗
PubMed1998

Urocortin in pregnancy.

OBJECTIVES: The aim of this study was to investigate the possibility that urocortin is the ligand that displaces corticotropin-releasing hormone from its binding protein in the maternal circulation during pregnancy and, if so, to determine whether urocortin, like corticotropin-releasing hormone, is synthesized in substantial quantities in the placenta. STUDY DESIGN: A radioimmunoassay specific for urocortin was developed and used for measurement of the peptide in chorionic villi and fetal membranes (amnion and chorion) from normal and preeclamptic pregnancies. These tissues were also assayed for corticotropin-releasing hormone. Assays for urocortin were also carried out on normal term pregnant and nonpregnant myometrium and on plasma from nonpregnant individuals, and assays for both peptides were performed on sequential normal pregnancy plasma samples taken from mid gestation until term. RESULTS: Corticotropin-releasing hormone was present in normal term (1904 +/- 489 pg/g) and preeclamptic placentas (5897 +/- 1526 pg/g) and in normal term fetal membranes (645 +/- 155 pg/g, n = 6 in all cases). Urocortin was not detected in any of the tissues studied, nor was it found in the normal human plasma samples. Unlike the situation for corticotropin-releasing hormone, no pregnancy-related pattern was seen for urocortin in the plasma from pregnant women. CONCLUSIONS: Urocortin is not translated to any great extent in the pregnancy tissues investigated, nor is it present in the circulation of pregnant women in detectable amounts. Furthermore, it is unlikely that urocortin is responsible for the high maternal plasma levels of free corticotropin-releasing hormone circulating in the latter stages of pregnancy, but this does not preclude the possibility that another, as yet uncharacterized, corticotropin-releasing hormone-like peptide may be.

Animals↗
PubMed1988

Prenatal diagnosis of thalassemia: experiences at the Shanghai Children's Hospital.

Using DNA dot-blot hybridization, restriction endonuclease gene mapping with oligonucleotide probes, restriction fragment length polymorphism linkage analysis, and hybridization, prenatal diagnosis was performed for 32 pregnancies at risk for alpha-thalassemia and for 10 pregnancies at risk for beta-thalassemia. The DNA samples were prepared from chorion villi or amniotic fluid cells.

Amnion↗
PubMed1985

Histopathologic changes in tubal pregnancy.

The histopathology of 110 cases of tubal gestation was reviewed. No evidence was found of the development of the gestation into the tubal muscularis and beneath the overlying peritoneum. The localized tubal mass identified clinically was secondary to luminal distention. It was clear that tubal rupture occurred secondary to localized distention and vascular compromise with hemorrhagic necrosis and was not secondary to invading chorionic villi. With conservative linear salpingostomy, the localized tubal damage histologically appeared to be about the same as that seen in spontaneous rupture. Difficulty in controlling bleeding in conservative surgical procedures may well be a reflection of the viability of the villi and implantation of the more vascular, mesenteric side of the tubal lumen.

Chorionic Villi↗
PubMed1985

[Krabbe's disease: globoid cell leukodystrophy. Clinical and prenatal diagnosis].

A 9 weeks old boy with infantile globoid cell leukodystrophy is presented. Clinical features consisted of insufficient weight gain, hypertonic musculature, irritability, loss of previously attained skills, loss of visual function, elevation of the cerebrospinal fluid (CSF) protein. He died at the age of 11 months. First-trimester diagnosis was performed in two consecutive pregnancies by means of analysis of chorionic villi in the 9th week.

Chorionic Villi↗
PubMedDate not supplied

[Morphofunctional placental characteristics in pregnant women with chronic pyelonephritis and urogenital chlamydia infection].

Morphological features of the placenta were studied in women with chronic pyelonephritis and urogenital chlamydial infection. There was an appreciable amount of chaotic sclerotic villi and symplastic nephroses reflecting compensatory-adaptive processes. Morphometric study of the afterbirths has shown that placenta affected with urogenital infection has large area of the intervillous space and small area of chorionic villi involved in gas exchange, supply of nutrients and other components to the fetus.

Chlamydia Infections↗
PubMed1989

Hormonal and basement membrane markers for immunoidentification of cultured human trophoblast cells.

Improvement of human chorionic villi cells in vitro culture has been obtained by supplementing the medium with 30% human fetal cord serum, instead of fetal calf serum. Expression of human chorionic gonadotropin, estrogen and progesterone receptors, laminin, laminin receptors, and type IV collagen has been studied on first subculture passages (4-7 weeks) by immunoperoxidase method. A minority of the cultured cells were positive for estrogen receptors, the majority were positive for progesterone receptors, while all cells were negative for human chorionic gonadotropin. Cultured cells showed variable positive immunostaining for basement membrane markers like laminin, and type IV collagen, and for laminin receptors. Detection of both progesterone receptors and laminin, or type IV collagen, excluded fibroblast contamination and could then be useful for quick identification of cultured trophoblast cells.

Basement Membrane↗
PubMed1999

[Genetic counseling and prenatal diagnosis in mitochondrial diseases].

Since mitochondrial diseases lead frequently to severe phenotypes and are often hereditary, there is a need for genetic counselling of the affected families. The specific features of mitochondrial genetics, however, hamper straightforward definition of recurrence risks as in Mendelian diseases. Empirical risks were recently provided for MELAS and MERRF syndromes and for Leber hereditary optic neuropathy. In MELAS and MERFF, higher levels of mutant mtDNA in the mothers' blood were associated with an increased frequency of affected offspring. Chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome are in general sporadic disorders without increased recurrence risks in the offspring. As Leigh syndrome is found with maternal, autosomal recessive or X chromosomal transmission, the definition of the molecular defect is crucial for genetic counselling. Prenatal diagnosis was reported only in one case of mitochondrial disease so far, and in our opinion it remains questionable because of the uncertain correlation of the proportion of mutant DNA in chorionic villi and in clinically relevant tissues such as brain.

Adolescent↗
PubMedDate not supplied

A three-dimensional study of the normal human placental villous core: II. Stromal architecture.

The three-dimensional architecture of the villous core of the chorionic villi has been studied in the human placenta throughout pregnancy by scanning electron microscopy, and compared with light microscopic and transmission electron microscopic, findings. Five different types of villi are recognizable: the mesenchymal villi are characterized by a network of tiny bundles of collagen fibrils, enmeshing mesenchymal cells, Hofbauer cells and vessels. The immature intermediate villi display a system of intercommunicating channels, parallel to the major axis of the villi. Within the channels, Hofbauer cells are present. The mature intermediate villi show narrow and short stromal channels, surrounded by a rather tight network of collagen fibrils. Large vessels and a highly compact network of collagen are typical of the stem villi. The terminal villi contain sinusoidally dilated capillaries and a small amount of connective tissue. These findings have numerous functional implications. They are particularly related both to the presence of the stromal channels which could facilitate the macrophagic and immunological task of the Hofbauer cells, and to the different types of villi, playing different roles in placental and fetal life, under normal and pathological conditions.

Chorionic Villi↗