997 resultados para fetal membranes


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Fetal membranes consist of 10 distinct layers including components of amnion, chorion and decidua, the latter being of maternal origin. They form mechanically integrated sheets capable of retaining amniotic fluid and play an essential role in protecting fetal growth and development in the pregnant uterus. The extracellular matrix, substrate for plasminogen activators (PAs), is an important supportive framework of the fetal membranes. :Fetal membranes from women with preterm premature rupture of membranes may differ in their protease activity compared with normal membranes. To identify the presence of PAs and their inhibitors (PAI) and their possible role in the process of fetal membrane rupture, this study in investigated the distribution and localization of both protein and mRNA for tissue (t) and urokinase (u) PA and their inhibitors type 1 (PAI-1) and type 2 (PAI-2) in amniochorion of human and rhesus monkey using conventional and. confocal immunofluorescence microscopy. In situ hybridization analysis showed that the distribution and localization of mRNAs for tPA, uPA, PAI-I and PAI-2 were similar in the fetal membranes of human and rhesus monkey; no obvious species difference was observed. Evidence of tPA mRNA was detected in amniotic epithelium, trophoblast cells and nearly all cells of the decidual layer. Strong expression of uPA mRNA was noted in the decidual cells which increased in intensity as the abscission point was approached. Weak staining in chorion laeve trophoblast was also detected. In situ hybridization experiments showed PAI-1 mRNA to be concentrated mainly in the decidual cells, some of which were interposed into the maternal-facing edge of the chorion laeve. Maximal labelling of the decidua occurred towards the zone of abscission. Weak expression of PAI-1 mRNA nas also noted in some cells of the chorion laeve. The distribution of PAI-2 mRNA in amniochorion was also concentrated in the cells of the decidual layer, maximum expression of the mRNA was in the level of abscission. No detectable amount of mRNAs for tPA, uPA, PAI-1 and PAI-2 was found in the fibroblast, reticular and spongy layers. Distribution of the proteins of tPA, uPA and PAI-1 in the fetal membranes of these two species was consistent with the distribution of their mRNA. Anti-PAI-2 immunofluorescence was found to be strongly concentrated in the amniotic epithelium, but PAI-2 mRNA was negative in this layer, suggesting that the epithelium-associated PAI-2 is not of epithelial origin. These findings suggest that a local fibrinolysis in fetal membranes generated by precisely balanced expression of PAs and their inhibitors via paracrine or autocrine mechanisms may play an essential role in fetal membrane development, maturation and in membrane rupture. Following an analysis of the distribution and synthesis of activators and inhibitors it was found that they may play a role in abscission during the third stage of labour. (C) 1998 W. B. Saunders Company Ltd.

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Problem The most common DNA lesion generated by oxidative stress (OS) is 7, 8-dihydro-8-oxoguanine (8-oxoG) whose excision repair is performed by 8-oxoguanine glycosylase (OGG1). We investigated OGG1 expression changes in fetal membranes from spontaneous preterm birth (PTB) and preterm premature rupture of the membranes (pPROM) and its changes in vitro in normal fetal membranes exposed to OS inducer water-soluble cigarette smoke extract (CSE). Method of study DNA damage was determined in amnion cells treated with CSE by comet and FLARE assays. OGG1 mRNA expression and localization in fetal membranes from clinical specimens and in normal term membranes exposed to CSE were examined by QRT-PCR and by immunohistochemistry. Results DNA strand and base damage was seen in amnion cells exposed to CSE. OGG1 expression was 2.5-fold higher in PTB samples compared with pPROM (P=0.045). No significant difference was seen between term and pPROM or PTB and term. CSE treatment showed a nonsignificant decrease in OGG1. OGG1 was localized to both amnion and chorion with less intense staining in pPROM and CSE-treated membranes. Conclusion Increased OS-induced DNA damage predominated by 8-oxoG is likely to persist in fetal cells due to reduced availability of base excision repair enzyme OGG1. This can likely lead to fetal cell senescence associated with some adverse pregnancy outcome.

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OBJECTIVES: To study the expression and the function of the 11beta-hydroxysteroid dehydrogenase enzyme 1 (11beta-HSD1) and 2 (11beta-HSD2) in placenta and the fetal membranes from pregnancies with intrauterine growth restriction (IUGR) and from controls. METHODS: Amnion, chorion, decidua and cotyledon were separated from placenta; mRNA was analyzed by TaqMan real-time technology and proteins by Western blot; enzyme activities were measured by the conversion of 3H-cortisol to 3H-cortisone and vice versa. RESULTS: Predominant mRNA expression (p < 0.001) was found for 11beta-HSD1 in chorion and for 11beta-HSD2 in decidua and cotyledon. In pregnancies with IUGR, 11beta-HSD1 was upregulated in chorion (mean DeltaCt 11beta-HSD:18S mRNA 193.5 vs. 103.0 in controls respectively, p < 0.05) and 11beta-HSD2 was downregulated in decidua (mean DeltaCt 11beta-HSD2:18S mRNA 0.18 vs. 15.88 in controls respectively, p < 0.05). 11beta-HSD1 protein levels were reduced in amnion and 11beta-HSD1 and 11beta-HSD2 oxidase activity in decidua and cotyledon were reduced from pregnancies with IUGR. CONCLUSION: Reduced synthesis or activity of 11beta-HSD1 or 2 in cases of IUGR is shown in some but not in all tissues. The local mRNA expression of 11beta-HSD1 in chorion may reflect a mechanism on the post-transcriptional gene regulation to stimulate the formation of cortisone in IUGR. To provoke increasing activity with oxidase stimulators could be a future therapy in cases of IUGR.

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Background: The therapy of retained fetal membranes (RFM) is a controversial subject. In Switzerland, intrauterine antibiotics are routinely administered although their effect on fertility parameters is questionable. The objective of this study was to compare the post-partal period after a routine treatment of RFM in 2 groups: one group received a placebo additionally (A), whereas the other group received a phytotherapeutic substance (lime bark) (B) additionally. The routine treatment of RFM included an attempt to manually remove the fetal membranes (for a maximum of 5 min), intramuscular administration of oxytetracycline and intrauterine treatment with tetracycline. In case of an elevated rectal temperature (>39.0°C), an additional non-steroidal inflam-matory drug was allowed. Methods: Cows undergoing caesarean section, suffering from prolapse of the uterus, deep cervical or vaginal injuries, hypocalcaemia, and illnesses during the last 14 days before calving were excluded. Cows had to be more than 265 days pregnant. Only cows that were artificially inseminated after RFM were included. Group stratification was done according to the last number on the ear tag (even/uneven) with (n = 50) cows in group A and (n = 55) cows in group B. Results: The number of treatments after the initial treatment of RFM was not significantly different between groups. The median interval from calving to the first insemination was 77 days in group A compared to 82 days in group B (p = 0.72). The number of AI’s until conception was not significantly different between groups. The median number of days open was 89 days in group A compared to 96 days in group B (p = 0.57). The culling rate was not significantly different between groups. Conclusion: There was neither a difference between the groups concerning therapies within the first 50 days after RFM nor concerning the subsequent fertility variables.

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The aim of the study was to obtain the diagnostic and therapeutic approach among Swiss practitioners in cows with puerperal metritis and clinical endometritis (part 2). All members of the Association for ruminant health were contacted per email via the newsletter. The survey was completed by 128 veterinarians, partially responded by 140 veterinarians. The following main symptoms of puerperal metritis were stated by the practitioners: purulent vaginal discharge, fever and reduced appetite. A vaginal and rectal examination was performed to diagnose the disease. Usually, an intrauterine treatment with tetracycline or cefapirin was done. Parenteral administration of tetracycline or penicillin was often combined with PGF(2α), NSAIDS or cortisone. Clinical endometritis was also diagnosed by vaginal and rectal examination and the main symptom indicated was purulent vaginal discharge. The therapy consisted of the administration of PGF(2α), uterine infusions predominantly with cefapirin, and rarely with parenteral administration of antibiotics. Further diagnostic tools were not used and normally cows were not rechecked. The success of the therapy of puerperal metritis and clinical endometritis was judged to be satisfactory to excellent.

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The aim of this study was to obtain the diagnostic and therapeutic approach among Swiss practitioners in cows with retained fetal membranes (RFM) (part 1). All members of the Association for ruminant health were contacted per email via the newsletter. The survey was completed by 128 veterinarians, partially responded by 140 veterinarians. The manual removal of the fetal membranes is practiced by 129 of the responding veterinarians. Cows with/without fever are treated usually with intrauterine antibiotics. Cows with RFM with/without fever are most commonly treated parenterally with tetracycline or penicillin. The use of cephalosporins and quinolones in cows with fever is more common than in cows without fever. With the present results of the survey veterinarians should critically question the supposed benefits of the manual removal of the placenta and the use of antibiotics in cows with RFM.

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OBJECTIVE: Bacterial colonization of the fetal membranes and its role in pathogenesis of membrane rupture is poorly understood. Prior retrospective work revealed chorion layer thinning in preterm premature rupture of membranes (PPROM) subjects. Our objective was to prospectively examine fetal membrane chorion thinning and to correlate to bacterial presence in PPROM, preterm, and term subjects. STUDY DESIGN: Paired membrane samples (membrane rupture and membrane distant) were prospectively collected from: PPROM = 14, preterm labor (PTL = 8), preterm no labor (PTNL = 8), term labor (TL = 10), and term no labor (TNL = 8), subjects. Sections were probed with cytokeratin to identify fetal trophoblast layer of the chorion using immunohistochemistry. Fluorescence in situ hybridization was performed using broad range 16 s ribosomal RNA probe. Images were evaluated, chorion and choriodecidua were measured, and bacterial fluorescence scored. Chorion thinning and bacterial presence were compared among and between groups using Student's t-test, linear mixed effect model, and Poisson regression model (SAS Cary, NC). RESULTS: In all groups, the fetal chorion cellular layer was thinner at rupture compared to distant site (147.2 vs. 253.7 µm, p<0.0001). Further, chorion thinning was greatest among PPROM subjects compared to all other groups combined, regardless of site sampled [PPROM(114.9) vs. PTL(246.0) vs. PTNL(200.8) vs. TL(217.9) vs. TNL(246.5)]. Bacteria counts were highest among PPROM subjects compared to all other groups regardless of site sampled or histologic infection [PPROM(31) vs. PTL(9) vs. PTNL(7) vs. TL(7) vs. TNL(6)]. Among all subjects at both sites, bacterial counts were inversely correlated with chorion thinning, even excluding histologic chorioamnionitis (p<0.0001 and p = 0.05). CONCLUSIONS: Fetal chorion was uniformly thinner at rupture site compared to distant sites. In PPROM fetal chorion, we demonstrated pronounced global thinning. Although cause or consequence is uncertain, bacterial presence is greatest and inversely correlated with chorion thinning among PPROM subjects.

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In recent years, increased focus has been placed on the role of intrauterine infection and inflammation in the pathogenesis of fetal brain injury leading to neurodevelopmental disorders such as cerebral palsy. At present, the mechanisms by which inflammatory processes during pregnancy cause this effect on the fetus are poorly understood. Our previous work has indicated an association between experimentally-induced intrauterine infection, increased proinflammatory cytokines, and increased white matter injury in the guinea pig fetus. In order to further elucidate the pathways by which inflammation in the maternal system or the fetal membranes leads to fetal impairment, a number of studies investigating aspects of the disease process have been performed. These studies represent a body of work encompassing novel research and results in a number of human and animal studies. Using a guinea pig model of inflammation, increased amniotic fluid proinflammatory cytokines and fetal brain injury were found after a maternal inflammatory response was initiated using endotoxin. In order to more closely monitor the fetal response to chorioamnionitis, a model using the chronically catheterized fetal ovine was carried out. This study demonstrated the adverse effects on fetal white matter after intrauterine exposure to bacterial inoculation, though the physiological parameters of the fetus were relatively stable throughout the experimental protocol, even when challenged with intermittent hypoxic episodes. The placenta is an important mediator between mother and fetus during gestation, though its role in the inflammatory process is largely undefined. Studies on the placental role in the inflammatory process were undertaken, and the limited ability of proinflammatory cytokines and endotoxin to cross the placenta are detailed herein. Neurodevelopmental disorders can be monitored in animal models in order to determine effective disease models for characterization of injury and use in therapeutic strategies. Our characterizations of postnatal behaviour in the guinea pig model using motility monitoring and spatial memory testing have shown small but significant differences in pups exposed to inflammatory processes in utero. The data presented herein contributes a breadth of knowledge to the ongoing elucidation of the pathways by which fetal brain injury occurs. Determining the pathway of damage will lead to discovery of diagnostic criteria, while determining the vulnerabilities of the developing fetus is essential in formulating therapeutic options.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Objectives: To determine whether histologic chorioamnionitis is associated with changes in gene expression of TLR-1, -2, -4 and -6, and to describe the localization of these receptors in fetal membranes. Study design: A total of 135 amniochorion membranes with or without histologic chorioamnionitis from preterm or term deliveries were included. Fragments of membranes were submitted to total RNA extraction. RNA was reverse transcribed and the quantification of TLRs expression measured by real time PCR. Results: All amniochorion membranes expressed TLR-1 and TLR-4, whereas 99.1% of membranes expressed TLR-2 and 77.4% expressed TLR-6. TLR-1 and TLR-2 expressions were significantly higher in membranes with histologic chorioamnionitis as compared to membranes without chorioamnionitis in preterm pregnancies (p = 0.003 and p < 0.001, respectively). Among the membranes of term pregnancies there were no differences in the expressions of such receptors regardless of inflammatory status. Regarding TLR-4 and TLR-6 expression, there was no difference among membranes with or without histologic chorioamnionitis, regardless gestational age at delivery. TLR-1, TLR-2, TLR-4 and TLR-6 expressions were observed in amniotic epithelial, chorionic and decidual cells. Conclusion: Amniochorion membranes express TLR-1, TLR-2, TLR-4 and TLR-6 and increased expression of TLR-1 and TLR-2 is related to the presence of histologic chorioamnionitis in preterm pregnancies. This study provides further evidence that amniochorion membranes act as a mechanical barrier to microorganisms and as components of the innate immune system. © 2013 Elsevier B.V. All rights reserved.