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PubMedDate not supplied

Scanning electron microscopy of primate chorionic villi following ultrasonic microdissection.

Villi from human, macaque and baboon placentae were subjected to ultrasonication after prolonged osmication, and examined by scanning electron microscopy. The technique was often successful in removing the overlying trophoblast and revealing expanses of the trophoblastic basal lamina, a conclusion corroborated by transmission electron microscopy. These preparations bore a remarkable similarity in appearance to microvascular cast preparations of the fetal vasculature. Relatively straight parallel tubules appeared to correspond in position to the location of fetal vessels in intermediate villi, whereas portions of the basal laminae of terminal villi were in the form of convoluted, branched cylinders similar to SEM images of fetal capillaries of terminal villi. The basal lamina did not have evidence of pores as has been described in some basal laminae.

Animals↗
PubMed1992

[Chorionic villi sampling and prenatal diagnosis].

The authors report their experience of 790 villous specimens taken either early (for 430 cases) or late (360 cases) between 10 and 37 weeks of amenorrhea (WA) using a transabdominal syringe. In the early choriocentesis cases, they conclude that use of the transabdominal route after 12.5 WA, regardless of the position of the chorion, makes it possible significantly to reduce the rate of fetal loss which becomes similar to that for amniocentesis. Placentocentesis has been used at later stages, either for high-risk couples as an alternative to amniocentesis (183 cases), or in cases of ultrasound abnormalities (177 cases) as an alternative to amniocentesis or cordocentesis. Placentocentesis makes it possible to obtain the fetal karyotype very rapidly within 1 to 2 days.

Abortion, Spontaneous↗
PubMed1982

[Histological observations on the chorionic villi of the diabetic placenta].

The diabetic woman's placenta does not present a uniform, specific pattern of abnormality. However the most prominent features are as follows: 1) Only in scattered areas of diabetic villi there is evidence of enlarged domains of PAS positive depositions which alternatively could be related to a thickening of the trophoblastic basement membrane or to the presence of chorio-gonadotropic hormones, which are also PAS positive glycoproteins. 2) villi from full-term diabetic placentae often, but not necessarily show an abnormal degree of morphological maturity of the length of gestational period. Villi appear to be unduly immature. Their vascularisation is lacking, and, on account of that, full-term diabetic placentae villi are comparable with those found in the 2nd trimester normal placentae. 3) there is a tendency for there to be an excessive number of fibrinoid deposits closely related to the syncytiotrophoblast.

Chorionic Villi↗
PubMed1991

[Prenatal diagnosis with chorionic villi and placenta puncture biopsy in the 1st to 3d trimester of pregnancy: diagnostic value of chromosome studies].

Chorionic villus sampling and placental biopsies became established diagnostic alternatives to amniocentesis worldwide during the 80's. Safety and accuracy are the most important criteria for the evaluation of these newer techniques as compared to amniocentesis. We report on our experience with more than 3400 chromosome analyses between 1985 and 1990 from first to third trimester of pregnancy in a single centre. Most obvious is the higher frequency of mosaicism, which is often, but not always confined to the placenta. Mosaicism accounts for the overwhelming majority of all discrepant (so-called false negative or false positive) cytogenetic findings. The most important prerequisites for diagnostic accuracy of chromosome analyses are meticulous separation of villi immediately after the sampling procedure as well as simultaneous use of direct preparation and cell culture. If mosaicism is not taken as sound evidence for foetal aneuploidy, the accuracy of cytogenetic diagnoses after chorionic villus sampling and placental biopsies is in the same range as the one after amniocentesis.

Adult↗
PubMed1988

[Characteristics of the extracellular matrix in the formation of sclerosis of the chorionic villi (immunofluorescence studies)].

Distribution of the eight components of extracellular matrix in small villi of human placenta was studied with indirect immunofluorescence. Normal full-term pregnancy was found to present rough fibers and type I collagen conglomerates accumulated in the stromal center, while type III and V collagens occurred all over the villous surface. Stromal localization of type IV collagen was recorded as well as its presence in basal membranes of the epithelium and vessels. Fibronectin showed diffuse distribution concentrating along the vessels. Laminin, entactin and in lesser degree heparan sulphate proteoglycan were registered in epithelial and vascular basal membranes. Isolated sclerosis of the villi in pathological pregnancy involved stromal accumulation of type I, III collagens, small fragments of collagens type IV, V and fibronectin. Multiple sclerosis of adherent villi demonstrated hyalin-like conglomerates of various collagens and fibronectin filling up the stroma. Laminin, heparan sulphate proteoglycan and entactin were not observed at these sites.

Basement Membrane↗
PubMed1993

Prenatal diagnosis of a hypermethylated full fragile X mutation in chorionic villi of a male fetus.

Fragile X syndrome, one of the most common human genetic diseases, is characterised by a unique genetic mechanism which involves dynamic mutation because of a heritable unstable DNA sequence and abnormal DNA methylation. Direct detection of the dynamic mutation and its methylation status at the DNA level would facilitate reliable tests for prenatal and postnatal diagnosis of the disease and for carrier detection. However, it has been suggested that DNA methylation can not be used as the basis for prenatal diagnosis as the CpG island is not always methylated in chorionic villus DNA. We report here a male fetus exhibiting both extensive somatic heterogeneity and abnormal hypermethylation of the full fragile X mutation in chorionic villus DNA as well as in fetal tissue DNA. Our results indicate that both somatic heterogeneity and hypermethylation of the full fragile X mutation are events that are clearly detectable in the 11th to 12th week of pregnancy.

Blotting, Southern↗
PubMedDate not supplied

Experience with multiple approaches to the prenatal diagnosis of the fragile X syndrome: amniotic fluid, chorionic villi, fetal blood and molecular methods.

We have had experience with 160 prenatal diagnosis cases for the fragile X syndrome [fra(X)] or Martin-Bell Syndrome. In 140, amniotic fluid was utilized; 98 had a documented family history of fra(X). The 94 completed cases included 4 no growth; 56 males of which 7 were fra(X)-positive and 2 false-negative; 38 females of which 5 were fra(X) positive. There was no fra(X) positive result when a family history of mental retardation was not documented as fra(X). Molecular methods (RFLPs) were utilized in 10 amniotic fluid and 5 chorionic villus specimens (CVS). Percutaneous umbilical blood sampling was used in 2 negative cases and 1 fra(X) positive case because of timing, tissue culture failure or confirmation of another method. CVS were received in 13 cases, and RFLPs were utilized in 5 of the CVS cases. There was no positive fra(X) CVS chromosome result in males, 1 positive result in a female, but 2 false negatives were detected by RFLPs. On the basis of the results, it can be concluded that cytogenetic and molecular methods are complementary and best used together and that multiple approaches can enhance the efficiency and reliability of fra(X) prenatal diagnosis.

Amniocentesis↗
PubMed1985

A practical assessment of ultrasound-guided transcervical aspiration of chorionic villi and subsequent chromosomal analysis.

Aspiration biopsy of trophoblastic villi was performed on 56 patients immediately preceding suction termination of pregnancy, using a malleable metal cannula and ultrasound guidance. Villi were obtained from 47 patients (84%), with sampling success rising to 93% after experience. Immediate complications were noted in 14% of patients and correlated with placental positions situated furthest from the cervical canal. Karyotyping from cultured and/or direct preparations was attempted on the villus samples and was successful in 42. Clarity of the karyotypes obtained from direct preparations in this series was not found to be adequate for diagnostic purposes. A number of practical suggestions which facilitate chorion villus sampling are described.

Biopsy, Needle↗
PubMed1996

Neonatal and placental factors in relation to the mode of umbilical cord insertion. Stereological analysis of chorionic villi.

Neonatal and placental factors and compartment volumes of placental parenchyma in relation to variations of cord insertions in normal human placentae were examined. The results of our investigation suggest that the mode of umbilical cord insertion has no significant effect on examined components. Stated differences are probably the effect of biological variations during normal placental and fetal development.

Birth Weight↗
PubMed2003

Ultrastructural localization of aminopeptidase A/angiotensinase and placental leucine aminopeptidase/oxytocinase in chorionic villi of human placenta.

AIMS: Membrane-bound aminopeptidases in human placenta are thought to be involved in maintaining homeostasis during pregnancy by metabolizing bioactive peptides such as oxytocin and angiotensin at the interface between the fetus and mother. Because determining the precise localization of these enzymes is required to support this notion, we investigated the ultrastructural localization of two principal enzymes, aminopeptidase A (APA; EC 3.4.11.7)/angiotensinase and placental leucine aminopeptidase (P-LAP; EC 3.4.11.3)/oxytocinase in human first trimester and full-term placenta. METHODS: Immunohistochemical analysis using anti-P-LAP and anti-APA antibodies was performed on ultrathin frozen sections of fixed human placental villi. RESULTS: Transmission immunoelectron microscopy revealed that both enzymes were expressed on the surface of apical microvilli of syncytiotrophoblast cells and, to a lesser extent, on the basal infoldings. The location of the two enzymes did not vary between the first trimester and full-term placenta sections, while the staining intensities were slightly enhanced in full-term villi. CONCLUSIONS: Our observation that P-LAP and APA are present on the microvilli, which is a site of interaction between the mother and fetus, suggests possible involvement of these enzymes in cleaving peptide hormones from the fetus and mother in order to regulate bioactivity.

Adult↗
PubMedDate not supplied

Distribution of diploidy, polyploidy, and endoreduplication in fra(X) positive and negative lymphocytes, amniocytes, and chorionic villi.

Expression of fragile X [fra(X)] (q27.3) and endoreduplicated metaphases have been reported in methotrexate-treated (MTX) fra(X) cultures (Kerem B, Biotein R, Schaap T [1988]: Chromosoma 97: 6-10). Further, new data (Kimchi-Sarfaty C, Goitein R, Kerem B, Werner M, Medan B, Schaap T [1991]: Am J Med Genet, this issue) indicate that MTX may specifically induce polyploidy and endoreduplication in cells with the fra(X) mutation. To confirm and extend these results, we have studied short-term lymphocyte cultures incubated in M199, a folate deficient system, and RPMI-1640 in the presence and absence of 5-fluorodeoxyuridine (FUdR) exposure during the last day of a 4 day culture. No endoreduplicated cells were seen under these conditions and there was no change in the level of polyploidy. We also studied the distribution of polyploid and endoreduplicated cells in amniotic fluid and chorionic villus sample cultures from one fra(X) positive and 4 at-risk specimens. No increase in the incidence of polyploidy or endoreduplication was observed in cultures exposed to MTX for both 24 and 48 hours from a fra(X) positive amniotic fluid case. Cytogenetic results were fra(X) negative for the remaining 4 cases tested. There was significant discordance between our findings and those expected based on MTX-induced increased frequencies of polyploidy and endoreduplication. Thus, our studies do not confirm the reported correlation between the presence of FRAXA and increased frequencies of polyploidy and endoreduplication in MTX-exposed amniocyte cultures and there was no evidence for increased levels of polyploidy and endoreduplication in short-term fra(X) lymphocyte cultures exposed to non-MTX fra(X) induction.

Amniotic Fluid↗
PubMed1981

[Ultrastructural study of chorionic villi in maternal-fetal isoimmunity].

The Authors studied the Human normal full term placenta and in the feto-maternal Rh and ABO incompatibilities. In the Human normal full term placenta the sincitium trophoblastum coat shows the usual microvillosity and the normal cytoplasmatic organules; in the placenta of ABO isoimmunized subjects the sincitium trophoblastum coat is intensely vacuolyzated; in the placenta of Rh isoimmunized subjects the lamina sincitiale vacuolyzation is more evident in the basal side. Discussion on the morphology related to the placenta barrier function.

ABO Blood-Group System↗