Histological classification of chorionic villous vascularization in early pregnancy

BACKGROUND: The objective of the study was to assess the reproducibility of a new classification for early pregnancy chorionic villous vascularization (Grade: I, normal; IIA, mild hypoplasia; IIB, severe hypoplasia and III, avascular) for routine microscopic examination in daily clinical practice. METHODS: In this observational study, four observers scored first trimester chorionic villous vascularization. Scoring was performed in microscopic slides of chorionic tissue obtained by D&C in 30 patients with early pregnancy loss due to empty sac (n = 10), fetal death (n = 10) and termination of pregnancy (n = 10) using the new classification. Ultrasonographic measurement of trophoblastic thickness (TT) at the implantation site was available in all patients and in a reference group of 100 ongoing singleton pregnancies. The vascularization score could therefore be related to the TT. RESULTS: The new classification resulted in a good-to-excellent agreement in histological scoring (0.73-0.90) between investigators (kappa 0.64-0.86). TT was not related to either vascularization or pregnancy outcome and only partly to hydropic degeneration. CONCLUSION: The vascularization scoring system is a simple, valid and effective method for assessment of chorionic villous vascularization. It is helpful in understanding the underlying cause of pregnancy loss, as the classification can distinguish between normal and abnormal embryonic development. We did not find either a relation between TT and pregnancy outcome or between TT and vascularization.     

Vasculogenesis in complete and partial hydatidiform mole pregnancies studied with CD34 immunohistochemistry

BACKGROUND: Defective chorionic villous vascularization is present in pregnancies complicated by absent or abnormal embryonic development. The aim of this study was to investigate the embryonic and/or maternal genomic influence on vasculogenesis in diploid complete hydatidiform mole (CHM) and in triploid partial hydatidiform mole (PHM) in comparison with normal development. METHODS: Mean villous stromal area and functional vascular area, vessels with a lumen and haemangiogenetic cords, peripherally or centrally located were measured and counted in chorionic villi of 12 CHM, 12 normal pregnancies (termination of pregnancy, TOP) and 15 PHM of which nine were without an embryo (PHM-E) and six were with an embryo (PHM + E), using quantitative CD34 immunohistochemistry. RESULTS: TOP showed significantly more vessels per chorionic villus, centrally and peripherally located (median, range), than CHM, PHM-E and PHM + E (4.0, 0-9 versus 0.0, 0-11, 0.0, 0-18 and 1.0, 0-21). CHM showed significantly more centrally located cords than PHM-E, PHM + E and TOP (1.5, 0-22 versus 1.0, 0-15, 0.5, 0-8 and 1.0, 0-2). CONCLUSIONS: Initiation of chorionic villous vasculogenesis is independent of the maternal genome (CHM). The development of an embryo, however, is obligatory for the modulation of normal vascularization resulting in a well developed vasculosyncytial membrane.     

First trimester chorionic villi sampling and direct chromosome preparations

Chorionic villi sampling was performed on 52 patients prior to elective termination of their pregnancies. Villi were obtained in 42, and direct chromosome preparations were successful in 41 of them. The use of a mixture of 0.075 M potassium chloride and 1% sodium citrate in the ratio of 2:1 for hypotonic treatment and 40% acetic acid for cell dispersal yielded chromosomes with good morphology and G-bands.     

First trimester diagnosis of Pompe''s disease (glycogenosis type II) with normal outcome: assay of acid α-glucosidase in chorionic villous biopsy using antibodies

Prenatal diagnosis of glycogenosis type II was performed by direct assay of acid alpha-glucosidase (EC 3.2.1.20) in chorionic villous biopsy obtained by transcervical cannula aspiration from a pregnancy at risk in the 10th week of gestation. The exact value of the enzyme activity estimated by the use of antibody preparations for purified human liver acid alpha-glucosidase was in the heterozygous range, and so the homozygous enzyme deficiency could be excluded. The subsequent analysis of cells cultured from amniocentesis sampling in the 18th week of gestation resulted in a similar outcome. The study with antibodies showed that in 23 control chorionic villi obtained during gestational ages between 7-13 weeks, 1-15% of the total alpha-glucosidase activity at pH 4.0 were due to renal or neutral enzyme. This indicates that it may be important to employ antibodies for prenatal diagnosis using chorionic villous sampling. A healthy and unaffected boy was born. The biochemical values obtained from an umbilical blood specimen were in accordance with the results of the prenatal diagnosis.     

厦门地区81例胚胎停育患者绒毛组织细胞遗传学分析

目的分析胚胎停育与绒毛组织细胞染色体异常的关系,为临床诊治提供可靠的依据。方法对81例胚胎停育患者无菌条件下取绒毛组织进行细胞培养及染色体核型分析。结果 81例胚胎停育绒毛组织中培养成功77例,失败4例。其中,检出染色体核型异常18例,检出率为23.38%。结论胚胎绒毛染色体异常是引起胚胎停育的重要因素,故绒毛组织细胞遗传学分析对查明流产原因,合理指导下次妊娠有重要意义。     

Characterization of human villous and extravillous trophoblasts isolated from first trimester placenta

Trophoblasts of the human placenta differentiate along two pathways to give either extravillous cytotrophoblasts (EVCT) with invasive properties and that are implicated in the implantation process, or villous cytotrophoblasts (VCT) that by cell fusion form multinucleated syncytiotrophoblasts. We report the first isolation and purification of these two cell types from the same chorionic villi of first trimester human placenta. We also studied their differentiation in vitro. Electron microscopy showed that in contrast to VCT, EVCT had no microvilli but contained large fibrinoid inclusions. EVCT cultures required a matrix to invade, and as previously established, VCT cultured on plastic dishes aggregated and fused to form syncytiotrophoblasts. These differentiation processes were characterized by a particular pattern of gene expression as assessed by real-time PCR and confirmed by immunocytochemical analysis of the corresponding proteins. EVCT cultured in vitro expressed high levels of HLA-G, c-erbB2, human placental lactogen, and very little human chorionic gonadotropin. Interestingly, TGFbeta2 was a marker of EVCT in vitro and in situ. These data offer a new tool for cell biologists to study the molecular mechanisms involved in human placental development and its pathology.     

The development of the human placental villous tree

Summary The present investigation was undertaken in order to achieve a better understanding of the dynamics of placental villous differentiation. Villous trees from human placentas from different stages of pregnancy (first trimester to full term) were isolated and studied by light microscopy and scanning electron microscopy. For light microscopy the trees were serially sectioned and two-dimensionally reconstructed. For scanning electron microscopy complete villous trees or freeze-cracked villi were studied.The most important finding was that the mesenchymal villi are continuously newly formed out of the trophoblastic sprouts throughout pregnancy. Because of this they exist in all stages of pregnancy and have to be considered the basis for growth and differentiation of the villous trees. In the first two trimesters they are the forerunners of the immature intermediate villi, whereas in the last trimester the mesenchymal villi are transformed into mature intermediate villi. The immature intermediate villi formed during the first two trimesters are developmental steps towards the stem villi. On the other hand, the mature intermediate villi, which only are developed during the last trimester, produce numerous terminal villi. The latter are not active outgrowths caused by proliferation of the trophoblast, but rather passive protrusions induced by capillary coiling due to excessive longitudinal growth of the fetal capillaries within the mature intermediate villi.     

Effect of 1-34 human parathyroid hormone upon first trimester placental human chorionic gonadotrophin secretion in vitro: potentiation by epidermal growth factor

Human chorionic gonadotrophin (HCG) secretion by the early placentais under multifactorial control. Epidermal growth factor (EGF)has been reported to be involved in regulating the formationand secretion of HCG by first trimester placental explants inculture. The effect of the amino-terminal fragment of parathyroidhormone (1–34 PTH), a calciotrophic factor upon HCG secretion,and its possible interaction with EGF were examined in thisstudy, both in static cultures and in superfusion, where ithas previously been demonstrated that HCG secretion is spontaneouslypulsatile. Gestational age-dependent effects of 1–34 PTHwere noted in both models. In static cultures, 1–34 PTHstimulated HCG secretion in 7–9 week placenta, in a biphasicfashion, the maximal effect being noted at 10–25 ng/mlconcentrations (250–270%), while at 1 and 100 ng/ml, theeffect was mild. In superfusion, the effect of 1–34 PTHadded overnight was also stimulatory, as shown by the significantlyincreased pulse amplitude and area under the curve. Effectsof 1–34 PTH at 11–14 weeks were inhibitory. In staticcultures at 7–9 weeks, the stimulatory effect of 25 ng1–34 PTH was increased by 70% when EGF (100 ng/ml) wasadded. However at 11–14 weeks, this combined effect wasinhibitory. We conclude that 1–34 PTH has an endocrineeffect on secretion of HCG by the first trimester placentaltissue, and this effect is potentiated by the addition of EGF.     

Histochemical and morphological examination of proliferation and apoptosis in human first trimester villous trophoblast

BACKGROUND: Our present knowledge about trophoblast turnover in human first trimester placental villi based on multiparametric examination of proliferation and apoptosis is limited. METHODS: Human villous placentae collected during 6, 7 and 8 weeks (n = 10/each group) of gestation were examined for trophoblast proliferation and apoptosis based on quantitative analyses of immunopositive Fas, tumor necrosis factor receptor 1 (TNFR1), cytokeratin 18 fragment (18f), number of proliferating cell nuclear antigen (PCNA), Ki67 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) positive nuclei, scores of mitotic and apoptotic indices and ultrastructural characteristics. RESULTS: Mitotic index in cytotrophoblast higher (P < 0.05) at 6 week compared with 7 and 8 weeks of gestation showed significant (P < 0.05) negative correlation between its prevalence and gestational age. Syncytiotrophoblast exhibited higher number of TUNEL positive nuclei (P < 0.01), TUNEL positive apoptotic nuclei (P < 0.05) and apoptotic index (P < 0.05) compared with cytotrophoblast at same gestational age. Positive correlations found between cytokeratin 18f and apoptotic index (P < 0.01), Fas and apoptotic index (P < 0.01), TUNEL positive nuclei and apoptotic index (P < 0.05), cytokeratin 18f and Fas (P < 0.01), whereas cytokeratin 18f (P < 0.05) and Fas (P < 0.05) showed positive correlation only with TUNEL positive apoptotic nuclear data. Phalangeal intrusions of syncytiotrophoblast between transitional cytotrophoblasts showed apposed plasma membranes bearing thickened membrane leaflets, inter-membranous gaps enclosing membranous invaginations, liposome-like particles; patches of membrane seen to be dissolved resulting in cytoplasmic continuity typical of syncytial formation. CONCLUSION: Cellular remodeling of first trimester villous placenta requires a complex homeodynamics involving proliferation in cytotrophoblast, development-associated syncytialization and apoptosis in syncytiotrophoblast.     

Modulation of human chorionic gonadotrophin bioactivity during the first trimester of pregnancy

The objective of this study was to evaluate the bioactivity of human chorionic gonadotrophin (HCG) during first trimester pregnancy. This was done by means of a retrospective analysis of sera from patients with first trimester normal intrauterine and ectopic pregnancies. Serum samples were obtained from 38 women with amenorrhoea of <10 weeks. From these, 19 had a normal intrauterine pregnancy (IUP) and 19 an ectopic pregnancy (EP). Cases were allocated to either low serum immunoreactive HCG (HCGi), intermediate HCGi or high HCGi concentrations (HCGi <5000 mUI/ml, between 5000 and 40,000 mIU/ml and >40,000 mIU/ml respectively). HCGi and oestradiol were measured by enzyme immunoassays and bioactive HCG by the mouse Leydig cell bioassay. All results were analysed by analysis of variance and unpaired Student's t-test. There was a significant difference between bioactive to immunoreactive HCG ratios (b/i ratio) between the subgroups of low, intermediate and high HCGi concentrations. Lower b/i ratios were found when HCGi concentrations were high (HCG b/i mean +/- SEM: high subgroup, 0.33 +/- 0.07 versus low subgroup: 1.50 +/- 0.12; P < 0.0001). Furthermore, the b/i ratios were inversely correlated with oestradiol (P < 0.0001) and HCGi (P < 0.0001) concentrations but not with gestational age. There was no difference in the b/i ratios when comparing IUP with EP. It is concluded that, in first trimester pregnancies, there is a likely modulation of HCG bioactivity which is inversely correlated with HCGi and oestradiol concentration. The underlying mechanisms and their physiological relevance remain to be elucidated.      

Urothelial tumors with villous morphology: Histomorphology and role of immunohistochemistry in diagnosis

Villous adenoma and urothelial carcinoma with villoglandular differentiation (UCVGD) are rare urothelial tumours showing villous morphology, the former being a preneoplastic entity and the latter being a malignant one. The detailed immunohistochemistry of these entities is previously not described in the literature. Moreover, a limited biopsy sample of UCVGD or a villous adenoma with or without adenocarcinoma may be difficult to distinguish on the basis of the histomorphology alone. An immunohistochemical panel comprising of GATA3, p63, β‐catenin, CK7 and CK20 was performed on five cases of UCVGD and three cases of villous adenoma with the aim of studying the expression of the proteins thereby aiding in the diagnosis of these entities in a limited surgical pathology specimen. The mean age of UCVGD was 66.8 years and all the patients were male. All the cases of UCVGD were associated with high grade papillary urothelial carcinoma with lamina propria invasion. The immunohistochemical panel showed strong nuclear GATA3 expression in the urothelial component of UCVGD. Interestingly, the high grade and the low grade villoglandular components of UCVGD also expressed GATA3 (nuclear) with a progressive loss of expression from the high grade to the low grade component. The villous adenomas showed negativity or aberrant cytoplasmic positivity for GATA3. The β‐catenin showed a gradual loss of membranous expression from villous adenoma to low grade and high grade villoglandular components of UCVGD with a patchy membranous expression in the urothelial component of the UCVGD. p63 showed strong nuclear positivity in the urothelial component and uniform negativity in the villous adenoma and villoglandular component of UCVGD irrespective of its grade, thereby distinguishing the villoglandular component from the urothelial component. The urothelial component of UCVGD showed strong membranous CK7 expression and was higher than the CK20 expression in the urothelial component. In contrast, CK20 expression was higher in villous adenoma as compared to CK7. There was no difference in the expression of CK7 and CK20 in the villoglandular components and low grade and high grade villoglandular areas. The above‐mentioned immunohistochemical pattern may help to distinguish the UCVGD from the villous adenoma.     

First trimester listeriosis with normal fetal outcome

The case of a pregnant woman who in the 13th week of gestation presented with a non-specific influenza-like illness ultimately proven to be symptomatic ofListeria monocytogenes septicemia, is described. The patient elected to continue the pregnancy and following antibiotic therapy recovered and delivered a normal infant. At 18 months of age the child was healthy with normal psychomotor development. This case underscores the need to consider the possibility ofListeria monocytogenes septicemia at any stage of pregnancy, and suggests that early institution of antibiotic treatment may result in complete recovery of both mother and fetus.     

Factors controlling spontaneous human chorionic gonadotrophin in superfused first trimester placental explants.

We have recently reported that secretion of human chorionic gonadotrophin (HCG) by placental explants in superfusion is pulsatile. In this study, the factors involved in regulation of spontaneous pulsatility were examined. In superfusion, observed secretion of HCG by isolated cells was continuous, without spontaneous episodic hormonal secretion. However, this was not due to diminished viability of the cells since these cells continued to secrete sex steroids. In addition, the stimulatory response of HCG to a highly effective dose of 10(-9) M gonadotrophin releasing hormone (GnRH) analogue was also maintained. Preincubation of explants with low concentrations of cycloheximide (10(-6)M) markedly reduced baseline HCG levels as well as pulse amplitude, suggesting that episodic hormone secretion is in part dependent on protein synthesis. Moreover, preincubation of explants with labelled leucine has shown that the secretion of placental proteins is also episodic in superfusion. The pattern was similar but not identical to that of HCG. Addition of 1 min pulses of CaCl2 caused a significant release of HCG by superfused explants, suggesting that HCG secretion occurs through the release of storage granules. It was concluded that for the expression of spontaneous pulsatile secretion of HCG cell to cell contact/communication is necessary. HCG secretion is likely to reflect exocytosis of storage granules. HCG pulsatility is partly dependent on protein synthesis and this intermittent type of secretion can be documented by overall protein secretion by the superfused explant.     

Subpopulation structure of human T lymphocytes studied with monoclonal antibody CD27

Institute of Immunology, Ministry of Health of Russian. (Presented by Academician of the Russian Academy of Medical Sciences R. V. Petrov.) Translated from Byulleten Éksperimental'noi Biologii i Meditsiny, Vol. 114, No. 11, pp. 506–508, November, 1992.