Placental Tissue (placental + tissue)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Allometric studies on growth and development of the human placenta: growth of tissue compartments and diffusive conductances in relation to placental volume and fetal mass

Terry M. Mayhew
Abstract Correlations between placental size and fetal mass during gestation fail to account for changes in composition that accompany placental growth and maturation. This study uses stereological data on the sizes of different tissue compartments in human placentas from 10 weeks of gestation to term and relates them to placental volume and to fetal mass by means of allometric analysis. In addition, tissue dimensions are used to calculate a physiological transport measure (diffusive conductance) for the villous membrane. Histological sections randomly sampled from placentas and analysed stereologically provided estimates of structural quantities (volumes, exchange surface areas, lengths, numbers of nuclei, diffusion distances). These data were combined with a physicochemical quantity (Krogh's diffusion coefficient) in order to estimate oxygen diffusive conductances for the villous membrane and its two components (trophoblast and stroma). Allometric relationships between these quantities and placental volume or fetal mass were obtained by linear regression analyses after log-transformation. Placental tissues had different growth trajectories: most grew more rapidly than placental volume and all grew more slowly than fetal mass. Diffusion distances were inversely related to placental and fetal size. Differential growth impacted on diffusive conductances, which, again, did not improve commensurately with placental volume but did match exactly growth of the fetus. Findings show that successful integration between supply and demand can be achieved by differential tissue growth. Allometric analysis of results from recent studies on the murine placenta suggest further that diffusive conductances may also be matched to fetal mass during gestation and to fetal mass at term across species. [source]

Role of a fetal defence mechanism against oxidative stress in the aetiology of preeclampsia

Christoph Jan Wruck
Aims:, Increasing evidence suggests that oxidative stress may play a key role in the aetiology of preeclampsia (PE). The aim of this study was to elucidate the placental defence mechanisms employed against oxidative stress and, in particular, the specific role of nuclear factor erythroid 2-related factor 2 (Nrf2). Methods and results:, Expression of Nrf2 in third-trimester placental tissue was compared in preeclamptic and normal gestation-matched controls. PE was associated with increased Nrf2 activity within cytotrophoblastic nuclei. Nrf2 expression was restricted to proliferative and early post-proliferative cytotrophoblast only. Syncytiotrophoblast was immunonegative for Nrf2 in both controls and preeclamptic placentas. Conclusions:, Nrf2 is exclusively active within cytotrophoblast, strongly suggesting that these cells are the origin of Nrf2-dependent gene products. Syncytiotrophoblast is transcriptionally inactive; therefore in times of oxidative stress essential cytoprotective enzymes must be derived from the cytotrophoblast. Excessive cytotrophoblastic turnover causes disproportionate release of toxic placental factors, manifesting as PE and endangering maternal health. Increased cytotrophoblastic proliferation/fusion could thus be interpreted as a fetal defence mechanism, initiated in response to the requirements of vulnerable syncytiotrophoblast. We therefore propose a direct relationship between fetal defence against oxidative stress and consequent placental toxicity as part of the aetiology of this complex maternal disease. [source]

Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin,

Sandra Stasenko
Abstract Cadmium and other metallic ions can act as metalloestrogens and endocrine disruptors of reproductive tissues and fetal development in mammals, including humans. The detrimental effects occur with respect to the synthesis of both steroid and polypeptide hormones in the placenta. Leptin is produced by the trophoblast and may regulate fetal organogenesis and development. In human term placentas, concentrations of toxic metals and their effects on steroidogenesis were assessed in healthy parturients (109 non-smokers and 99 smokers) in relation to tobacco smoking. Trace elements (cadmium, lead, iron, zinc and copper) were analyzed in placentas using atomic absorption spectroscopy, and steroid hormones (progesterone and estradiol) were assayed in placental samples by an enzyme-immunometric method. Cadmium concentrations were doubled in placentas of smokers as compared with non-smokers, and placental lead and zinc concentrations increased significantly. Placental concentrations of iron, copper, progesterone and estradiol did not differ. In addition, human trophoblast cells were co-cultured with 0, 5, 10 or 20,,m CdCl2 for 96,,h and leptin mRNA assessed by quantitative polymerase chain reaction. Leptin mRNA declined dose-responsively as a result of CdCl2 exposure. Collectively, the results confirm that human placental tissue offers a unique opportunity to biomonitor cadmium exposure in both the maternal and the internal fetal environments. In addition, the results strongly suggest that cadmium may cause a decline in placental leptin synthesis, as we have previously shown for placental progesterone production. This may constitute further evidence of the endocrine-disrupting effects of cadmium, as a constituent of tobacco smoke, on reproduction in women. Copyright 2009 John Wiley & Sons, Ltd. [source]

Purification and partial characterization of xyloglucan-hydrolyzing enzymes from watermelon placental tissue

Yasar Karakurt
Abstract BACKGROUND: Watermelon (Citrullus lanatus (Thunb.) Matsum & Nakai) fruit matrix glycans are comprised largely of xyloglucans (XGs). As in other fruits, these polymers show significant molecular mass downshifts during ripening. In the present study, we describe the purification and characteristics of a number of xyloglucanases (XGases) from the placental tissue of ripe watermelon. XGases were extracted from watermelon fruit placental tissue and purified by sequential ion-exchange, gel-permeation and concanavalin A chromatography. RESULTS: Five XGases (P1S2, P2S2, P3S1, P3S2, P3S3) were recovered with molecular masses ranging from 30.5 to 77.5 kDa on SDS-PAGE. All XGases showed maximum activity at pH 5,5.5 and 35,40 C against tamarind seed XG and were also active against XG-rich matrix glycans from watermelon fruit. The enzymes were strongly inhibited by mercury and hydrolyzed XG without generation of oligomers or monomers. P3S3 had the highest activity against XG. The purified enzymes were active toward carboxymethylcellulose, indicating that they were not XG specific. CONCLUSION: The pattern of molecular mass downshifts during XG hydrolysis by the purified XGases and the absence of monomeric and oligomeric products are consistent with endo-type catalysis for the XGases and with a role for these enzymes in the degradation of cell wall XG during ethylene-induced watersoaking of watermelon fruit placental tissues. Copyright 2009 Society of Chemical Industry [source]

Tissue factor-dependent blood coagulation is enhanced following delivery irrespective of the mode of delivery

Summary. Background:,The risk of thrombosis is clearly increased in the postpartum period. Mice with a targeted deletion of the transmembrane domain of tissue factor (TF) develop serious activation of blood coagulation and widespread thrombosis after delivery. Objective and methods:,We hypothesized that TF, abundantly present in placental tissue, is released during delivery, resulting in the activation of blood coagulation. We measured sensitive markers for TF-dependent activation of coagulation before and after induction of labor in two groups: a vaginal delivery (VAG) group and a cesarean section (CS) group.Results:,One hour after delivery, soluble TF (sTF) significantly increased in both groups [VAG group (mean SD) 226 42 to 380 42 pg mL,1 and CS group 193 17 to 355 44 pg mL,1]. The day after delivery, sTF was somewhat less increased. Both groups also showed an increase in factor VIIa, indicating activation of the TF pathway of coagulation. Indeed, after delivery, TF-dependent coagulation, as measured by the TF clotting time assay, was significantly enhanced. Increased plasma levels of prothrombin fragment 1 + 2 and thrombin,antithrombin complexes demonstrated thrombin generation following delivery. TF pathway-dependent activation of coagulation upon delivery was not blocked by TF pathway inhibitor and was not dependent on the mode of delivery.Conclusion:,The postdelivery increase in TF-dependent activation of coagulation is likely to be a natural mechanism to prevent excessive blood loss during and after delivery, and may also indicate a novel mechanism by which puerperal women have an increased risk of venous thromboembolism. [source]

Tubal ectopic pregnancy associated with an adenomatoid tumor

Teruhiko Inoue
We present a case of coexistence of an ectopic pregnancy and an adenomatoid tumor in the same fallopian tube. The adenomatoid tumor is the most common benign neoplasm of the fallopian tube, and the vast majority of ectopic pregnancies occur in the fallopian tube. However, coexistence of these two conditions is extremely rare, and there has been only one previously reported case in the English literature. In the present case, the placental tissue, consisting of chorionic villi and decidua, was present in the ampulla, and the adenomatoid tumor was found in the myosalpinx, just proximal to the implantation site, replacing a large part of the myosalpinx. The close spatial relationship of these two lesions suggests that an adenomatoid tumor could have interfered with transportation of the fertilized ovum through the tube, possibly via impaired contractile activity of the myosalpinx, and consequently caused the ectopic tubal pregnancy. [source]

Familial monozygotic twinning: A report of seven pedigrees,

Geoffrey Machin
Abstract Seven families contained 19 MZ twin pairs (2.7 pairs/family), diagnosed by low-stringency variable number tandem repeats in DNA from placental tissue or blood. Chorion status was known in 10 pairs, 6 dichorionic, 4 monochorionic. Sex ratio was equal. Autosomal dominant inheritance is apparent. 2009 Wiley-Liss, Inc. [source]

Placental macrophage contact induces complete replicative cycle of human immunodeficiency virus in latently infected syncytiotrophoblast cells: role of interleukine-6 and tumor necrosis factor-,

Ferenc D. Tth
The phenotypic mixing between human immunodeficiency virus type 1 (HIV-1) and vesicular stomatitis virus (VSV) has been exploited to assay the susceptibility of human term syncytiotrophoblast cells to penetration by various strains of HIV-1. VSV (HIV-1IIIB) and VSV (HIV-1Ba-L) pseudotypes were found to enter syncytiotrophoblasts. Infection of syncytiotrophoblasts was mediated by envelope glycoproteins of IIIB and Ba-L strains of HIV-1. Although certain strains of HIV-1 could enter syncytiotrophoblasts, the cells did not exhibit permissiveness for HIV-1. The next studies tested the possibility that placental macrophages might induce replication of HIV-1 carried in syncytiotrophoblast cells and that infected syncytiotrophoblasts would be capable of transmitting virus into neighbouring macrophages. For this purpose, the macrophage-tropic Ba-L strain of HIV-1 was used. Interactions between syncytiotrophoblasts and macrophages activated HIV-1 from latency in syncytiotrophoblast cells, which delivered HIV-1 to cocultured macrophages. The stimulatory effect of coculture on HIV-1 gene expression was mediated by marked tumor necrosis factor-, and interleukin-6 release from macrophages, an effect caused by contact between the different placental cells. Results suggest an interactive role for the syncytiotrophoblast layer and placental macrophages in the dissemination of HIV-1 among placental tissue. [source]

The human placenta from heavy smokers: evaluation of vasoactive peptides by immunohistochemistry,

APMIS, Issue 1 2007
The study aimed to demonstrate the expression of nitric oxide converting enzyme, nitric oxide synthase (e-NOS), and endothelin-1 (Et-1) in formalin-fixed paraffin-embedded placental tissue, and to demonstrate a difference in staining intensity between heavy smokers and non-smokers. Term placentas from pregnancies from otherwise healthy women smoking 15 or more cigarettes per day (heavy smokers) and term placentas from a matching group of non-smokers were included. The antibodies for Et-1 and e-NOS are recommended for cryostat sections. We evaluated the antibodies on paraffin-embedded tissue combined with the streptavidin-biotin-peroxidase technique. Et-1 and e-NOS were demonstrated in the placental vasculature, the trophoblast, and the amnion. A blinded comparative study showed no reproducible significant differences in the staining intensity of the antigen-antibody reaction to Et-1 and e-NOS between the two groups. [source]

Decreased expression of heparin-binding epidermal growth factor,like growth factor as a newly identified pathogenic mechanism of antiphospholipid-mediated defective placentation

N. Di Simone
Objective Heparin-binding epidermal growth factor,like growth factor (HB-EGF) plays a role in blastocyst implantation and is down-regulated in preeclampsia and in hypertensive pregnancy disorders associated with defective extravillous trophoblast invasion. Defective placentation and severe preeclampsia are also features of the antiphospholipid syndrome (APS). The purpose of this study was to investigate whether abnormal HB-EGF expression plays a pathogenic role in antiphospholipid antibody (aPL),mediated defective placentation. Methods HB-EGF expression in placental tissue was evaluated by Western blotting and messenger RNA analysis in normal and APS placentae. Polyclonal IgG fractions or monoclonal ,2 -glycoprotein I,dependent aPL and their respective controls were investigated for the following 4 features: their binding to human trophoblast monolayers, as determined by cell enzyme-linked immunosorbent assay (ELISA); their effect on HB-EGF expression by Western blotting in trophoblast cell extracts as well as by ELISA as a protein secreted in the culture supernatants; their inhibitory effect on in vitro trophoblast invasiveness, as evaluated by Matrigel assay; and their inhibitory effect on matrix metalloproteinase (MMP) levels, as measured by gelatin zymography. Experiments were also performed in the presence of serial concentrations of heparin or recombinant HB-EGF. Results Placental APS tissue displayed reduced expression of HB-EGF. Polyclonal and monoclonal aPL bound to trophoblast monolayers and significantly reduced the in vitro synthesis and secretion of HB-EGF. Heparin inhibited aPL binding and restored HB-EGF expression in a dose-dependent manner. Addition of recombinant HB-EGF reduced the in vitro aPL-induced inhibition of Matrigel invasiveness as well as MMP-2 levels. Conclusion These preliminary findings suggest that the reduction of aPL-mediated HB-EGF represents an additional mechanism that is responsible for the defective placentation associated with APS and that heparin protects from aPL-induced damage by inhibiting antibody binding. [source]

Transport of Benzo[,]pyrene in the Dually Perfused Human Placenta Perfusion Model: Effect of Albumin in the Perfusion Medium

Line Mathiesen
Foetal exposure to this substance is highly relevant but is difficult to estimate. The human placenta is unique compared to other species; since it is available without major ethical obstacles, we have used the human placenta perfusion model to study transport from mother to foetus. Placentas were donated after births at Rigshospitalet in Copenhagen from pregnant mothers who signed an informed consent. BaP is lipophilic and studies using cell culture medium in 6-hr placenta perfusions showed minimal transport through the placenta. To increase the solubility of BaP in perfusion medium and to increase physiological relevance, perfusions were also performed with albumin added to the perfusion medium [2 and 30 mg/ml bovine serum albumin (BSA) and 30 mg/ml human serum albumin (HSA)]. The addition of albumin resulted in increased transfer of BaP from maternal to foetal reservoirs. The transfer was even higher in the presence of an HSA formulation containing acetyltryptophanate and caprylate, resulting in a foetal,maternal concentration (FM) ratio of 0.71 0.10 after 3 hr and 0.78 0.11 after 6 hr, whereas the FM ratio in perfusions without albumin was only 0.05 0.03 after 6 hr of perfusion. Less BaP accumulated in placental tissue in perfusions with added albumin. This shows that transplacental transport of the pro-carcinogenic substance BaP occurs, and emphasizes the importance of adding physiological concentrations of albumin when studying the transport of lipophilic substances. [source]

Serum iron and copper status and oxidative stress in severe and mild preeclampsia

Zehra Serdar
Abstract Our aim was to investigate parameters of iron and copper status and oxidative stress and antioxidant function in women with healthy pregnancy, mild and severe preeclampsia with a view to exploring the possible contribution of these parameters to the aetiology. Thirty healthy, 30 mild preeclamptic and 30 severe preeclamptic pregnant women were included. Serum and placental lipid peroxides, and serum vitamin E and total carotene levels were measured by colorimetric assay. Cholesterol, copper, iron, total iron binding capacity (TIBC), ceruloplasmin and transferrin concentrations were measured by commercially available procedures. Data were analysed statistically using one-way analysis of variance and Pearson correlation test. Logistic regression procedures were used to calculate odds ratios. Lipid peroxides in serum and placental tissue, and iron, copper and ceruloplasmin levels in serum were significantly increased, and transferrin, TIBC, vitamin E/total cholesterol and total carotene/total cholesterol ratios in serum were significantly decreased especially in women with severe preeclampsia. Significant correlations were detected between serum iron and lipid peroxidesin serum and placental tissue and between serum iron and vitamin E/total cholesterol in severe preeclamptic pregnancy. Furthermore, there were significant correlations between serum malondialdehyde and ceruloplasmin and vitamin E/total cholesterol in women with severe preeclampsia, and changes in serum and placental lipid peroxides and serumiron concentrations were significantly associated with preeclampsia. In conclusion, ischaemic placental tissue may be a primary source of potentially toxic iron in preeclampsia and the released iron species may contribute to the aetiology and would exacerbatelipid peroxidation and endothelial cell injury, which may be abated by antioxidant supplementation. Copyright 2005 John Wiley & Sons, Ltd. [source]

The sodium-iodide symporter expression in placental tissue at different gestational age: an immunohistochemical study

C. Di Cosmo
Summary Background, Iodide (I,) is crucial for foetal thyroid function. Foetal iodide results from maternal circulating iodide and from deiodination of iodothyronines within the placenta. The Na+/I, symporter (NIS) localized in placental cells appears to be involved in iodide exchange. Low NIS expression has been reported in trophoblast cells from the first trimester and pregnancy at term. Aims, The aim of this study was to examine NIS expression by immunohistochemistry in the major components of human ovular tissue and placenta. Materials and methods, Formalin-fixed and paraffin-embedded specimens of placental tissue from the first trimester and at term were analysed. NIS expression was quantified as percentage of NIS-positive cells/total cells. NIS expression was also evaluated by real-time polymerase chain reaction (RT-PCR) in five first-trimester and five at-term placental specimens. Results, In the first-trimester specimens heterogeneous NIS immunoreactivity was found in cyto-syncytiotrophoblast cells, with a range of NIS-positive cells from 5% to 80% (mean SD 2185 2395), in mesenchymal and endothelial cells from 1% to 40% (145 1116), in decidual cells from 5% to 40% (1038 1198) and in endometrial glands from 3% to 40% (2186 1393). In specimens from placenta at term, NIS-positive cyto-syncytiotrophoblast cells were between 5% and 40% (mean 1785 1815), mesenchymal and endothelial cells between 1% and 40% (1367 1216), decidual tissue between 5% and 30% (1643 908), and endometrial glands between 3% and 40% (1667 1527). No significant differences in NIS expression were observed between the first trimester and placenta at term. A similar level of mRNA expression for the NIS gene was obtained by RT-PCR both in ovular material of the first trimester and in placenta at term. Conclusions, We found NIS to be expressed in various placental and ovular components and its expression to remain constant during pregnancy. [source]

Purification and partial characterization of xyloglucan-hydrolyzing enzymes from watermelon placental tissue

Yasar Karakurt
Abstract BACKGROUND: Watermelon (Citrullus lanatus (Thunb.) Matsum & Nakai) fruit matrix glycans are comprised largely of xyloglucans (XGs). As in other fruits, these polymers show significant molecular mass downshifts during ripening. In the present study, we describe the purification and characteristics of a number of xyloglucanases (XGases) from the placental tissue of ripe watermelon. XGases were extracted from watermelon fruit placental tissue and purified by sequential ion-exchange, gel-permeation and concanavalin A chromatography. RESULTS: Five XGases (P1S2, P2S2, P3S1, P3S2, P3S3) were recovered with molecular masses ranging from 30.5 to 77.5 kDa on SDS-PAGE. All XGases showed maximum activity at pH 5,5.5 and 35,40 C against tamarind seed XG and were also active against XG-rich matrix glycans from watermelon fruit. The enzymes were strongly inhibited by mercury and hydrolyzed XG without generation of oligomers or monomers. P3S3 had the highest activity against XG. The purified enzymes were active toward carboxymethylcellulose, indicating that they were not XG specific. CONCLUSION: The pattern of molecular mass downshifts during XG hydrolysis by the purified XGases and the absence of monomeric and oligomeric products are consistent with endo-type catalysis for the XGases and with a role for these enzymes in the degradation of cell wall XG during ethylene-induced watersoaking of watermelon fruit placental tissues. Copyright 2009 Society of Chemical Industry [source]

Impaired cytotrophoblast cell,cell fusion is associated with reduced Syncytin and increased apoptosis in patients with placental dysfunction

Manuela Langbein
Abstract Preeclampsia (PE), Hemolysis Elevated Liver Enzymes and Low Platelets (HELLP)-syndrome, and intrauterine growth restriction (IUGR) are associated with abnormal placentation. In early pregnancy, placental cytotrophoblasts fuse and form multinuclear syncytiotrophoblasts. The envelope gene of the human endogenous retrovirus-W, Syncytin, is a key factor for mediating cell,cell fusion of cytotrophoblasts. This study investigated clinical parameters of PE and HELLP-associated IUGR and analyzed the cell,cell fusion index and ,-human chorionic gonadotropin (,-hCG) secretion of cytotrophoblasts isolated and cultured from placentas of these patients. In addition, we performed absolute quantitation of Syncytin and determined the apoptosis rate in both cultured cytotrophoblasts and placental tissues. Cultured cytotrophoblasts from PE and HELLP-associated IUGR correlated with a pronounced lower cell,cell fusion index, 1.8- and 3.6-fold; less nuclei per syncytiotrophoblast, 1.4- and 2.0-fold; a significantly decreased ,-hCG secretion, 4.3- and 17.2-fold and a reduction of Syncytin gene expression, 8.1 (P,=,0.019) and 222.7-fold (P,=,0.011) compared with controls, respectively. In contrast, a significantly 2.3-fold higher apoptosis rate was observed in cultured PE/IUGR cytotrophoblasts (P,=,0.043). Importantly, Syncytin gene expression in primary placental tissues of PE/IUGR was 5.4-fold lower (P,=,0.047) and in HELLP/IUGR 10.6-fold lower (P,=,0.019) along with a 1.8- and 1.9-fold significant increase in the apoptosis rate compared with controls, respectively. Low Syncytin expression in both cultured cytotrophoblasts and primary tissues from pathological placentas supports an intrinsic placenta-specific deregulation of cell,cell fusion in the formation of syncytiotrophoblasts leading to increased apoptosis. These processes could contribute to the development and severity of PE and HELLP-associated IUGR. Mol. Reprod. Dev. 75: 175,183, 2008. 2007 Wiley-Liss, Inc. [source]

Quantitative analysis of messenger RNA expression of matrix metalloproteinases (MMP-2 and MMP-9), tissue inhibitor-2 of matrix metalloproteinases (TIMP-2), and steroidogenic enzymes in bovine placentomes during gestation and postpartum

M. Takagi
Abstract The relationship between the mRNA expression of proteolytic and steroidogenic enzymes in bovine placentomes was examined. Caruncle and cotyledon tissues were collected every 6 hr after spontaneous parturition until the fetal membranes were released. Based on the time of fetal membrane release after parturition, the specimens were classified as follows: (1) the early group, in which the fetal membranes were released within 6 hr after parturition; and (2) the late group, in which the fetal membranes were released 6,12 hr after parturition. The placentomes from a slaughterhouse were additionally collected as samples for the examination of enzymes during the gestation period. The mRNA expression of steroidogenic enzymes in the cotyledon was observed to be higher than that in caruncle tissues; however, the mRNA expression patterns of P450scc and StAR tended to be similar in both placental tissues. On the other hand, although the expression levels of TIMP-2 mRNA in both caruncle and cotyledon tissues were similar, during gestation and postpartum the expression levels of MMP-2 and MMP-9 mRNA were approximately 10 times higher in caruncle than in cotyledon tissue. Marked contrasting changes in mRNA expression patterns between pre- and postpartum periods were observed for MMP-2 and MMP-9 in caruncle tissues and for MMP-9 and TIMP-2 in cotyledon tissues. The present study provides the first evidence that MMP-2, MMP-9, and TIMP-2 mRNAs are expressed in bovine placentomes during the gestational and postpartum periods and suggests that these enzymes, in conjunction with steriodogenic enzymes, mediate fetal membrane detachment after parturition. Mol. Reprod. Dev. 74: 801,807, 2007. 2006 Wiley-Liss, Inc. [source]

Expression of genes associated with allantois emergence in ovine and bovine conceptuses

A.M. Ledgard
Abstract In the development of ruminant embryos, the emergence and growth of the allantois is critical for the establishment of the chorioallantoic placenta. The allantoic membrane contributes to all the vasculature that perfuses the placental tissues and the fetal membranes. Using suppressive subtractive hybridization to compare mRNA from Day 13 ovine preimplantation conceptuses (prior to allantoic emergence) with Day 17 allantoic membrane, we identified nine genes whose expression was associated with the emergence of the allantoic sac. Collagen alpha 1 type XII, collagen alpha 2 type I, collagen alpha 2 type V, epsilon 4 beta-globin, osteonectin, and uroplakin were expressed at significantly greater levels in ovine Day 17 allantois compared to Day 13 conceptuses. These genes are associated with the extracellular matrix and most likely are involved in establishing and strengthening the structural integrity of the allantoic sac and in the development of the blood vessels. RalB expression increased with development although at significantly greater levels in the allantois only at Day 19. Hoxa-10 and RhoA showed no differential expression during this period. All these genes showed a similar temporal pattern of expression in bovine conceptuses at equivalent stages of development with significantly greater expression of all these genes, except for Hoxa-10, found in Day 24 allantois compared to Day 14 conceptuses. This suggests that the role they play in allantoic emergence, growth and function is conserved in both ruminant species and that their expression is regulated in a similar manner. The interactions and regulation of this process remains to be fully explained. Mol. Reprod. Dev. 1084,1093, 2006. 2006 Wiley-Liss, Inc. [source]

ORIGINAL ARTICLE: Temporal and Spatial Expression of Tumor-Associated Antigen RCAS1 in Pregnant Mouse Uterus

Ekaterine Tskitishvili
Citation Tskitishvili E, Nakamura H, Kinugasa-Taniguchi Y, Kanagawa T, Kimura T, Tomimatsu T, Shimoya K. Temporal and spatial expression of tumor-associated antigen RCAS1 in pregnant mouse uterus. Am J Reprod Immunol 2010; 63: 137,143 Problem, The tumor-associated antigen RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is considered to play a role in the inhibition of maternal immune response during pregnancy, and participates in the initiation of labor and placental detachment. The aim of our study was to investigate the expression of RCAS1 protein in the uteri of normal pregnant mice. Method of study, Uteri with fetuses were collected from pregnant ICR mice on days 1.5, 3.5, 5.5, 7.5, and 9.5 p.c., and uterine and placental tissues were obtained separately on days 11.5, 13.5, 15.5, and 17.5 p.c. Samples were examined using real-time (RT)-PCR, Western blotting, and immunohistochemical analyses. Results, In normal pregnant mice, RCAS1 protein mRNA was significantly increased on day 7.5 p.c. Antigen localization was detected in the placenta, decidua, and fetus. Conclusion, The results of this study suggest the importance of day 7.5 p.c. for RCAS1 protein expression in connection with placentation as a possible target for future in vivo studies. [source]

ORIGINAL ARTICLE: Placental Fas/Fas Ligand Expression in Early Pregnancy Losses

Emine Seda Guvendag Guven
Problem, The aim of this study was to compare the expression levels of Fas and Fas ligand (FasL) in first-trimester placentas obtained from spontaneous abortions in patients with antiphospholipid antibody syndrome (APS) or factor V (FV) Leiden mutation, compared with values in placentas from induced abortions in patients negative for these conditions. Method of study, We studied explants from 6- to 10-week-old placentas that had been prepared by collagenase digestion from 10 spontaneous abortions from APS-positive patients, nine spontaneous abortions in patients positive for FV Leiden mutation, and 10 induced abortions. All tissues were analyzed by flow cytometry for expression of Fas and FasL. Results, Flow cytometric analysis showed that placental FasL expression was significantly lower in abnormal pregnancies than in normal ones. However, no such difference was observed for Fas expression. Conclusion, FasL on placental cells may be involved in the maintenance of immune privilege, thereby ensuring the safety and growth of placental tissues. Dysregulation of apoptotic mechanisms may play a critical role in spontaneous abortions. [source]

Determination of didanosine in maternal plasma, amniotic fluid, fetal and placental tissues by high-performance liquid chromatography,tandem mass spectrometry

T. Nicole Clark
Abstract A rapid and efficient high-performance liquid chromatography (HPLC)-tandem mass spectrometry method for the determination of didanosine concentrations in maternal rat plasma, amniotic fluid, placental and fetal tissue samples has been developed and validated. Tissue samples were homogenized in optima water and centrifuged. The supernatant was subjected to solid-phase extraction (SPE) prior to analysis. Plasma and amniotic fluid samples were extracted without pretreatment. An Agilent 1100 Series HPLC coupled with a Micromass Quattro II triple quadrupole mass spectrometer was used for all analyses. Chromatographic resolution was achieved on a Nova-Pak phenyl analytical column (2.0 150 mm, 4 m particle size) equipped with a Phenomenex Security-guard phenyl guard cartridge (2.0 4.0 mm) using 60% methanol in 10 mm ammonium acetate buffer mobile phase for all matrices at a flow rate of 0.15 mL/min. The method yields retention times of 2.9 min for didanosine and 3.0 min for the internal standard, stavudine. Limits of detection were 1 ng/mL for all matrices. Recoveries were 70% or greater for both compounds in the different matrices. Within- and between-run precision (%RSD) and accuracy (%error) was less than 15% for all matrices. Copyright 2006 John Wiley & Sons, Ltd. [source]