Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMNION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1985

Steroid sulfatase activity in amnion tissue and amnion cells maintained in monolayer culture.

Phenolic steroid sulfatase activity in amnion tissue, amnion homogenate, subcellular fractions, and amnion epithelial cells in culture was demonstrated with radiolabeled estrone sulfate as the substrate. Sulfatase activity could not be detected in either amnion tissue or cells when evaluated with dehydroisoandrosterone sulfate as the substrate. Phenolic steroid sulfatase activity in amnion tissue was linear with incubation time up to 3 h and with amnion tissue weight up to 800 mg/ml. The rate of estrone sulfate hydrolysis in amnion tissue increased in a linear manner with temperature from 3 to 60 C. The apparent Km of amnion tissue sulfatase for estrone sulfate was 9 microM. The highest specific activity of the enzyme was found in both the mitochondrial-lysosomal and microsomal fractions. In studies with amnion epithelial cells in monolayer culture, phenolic steroid sulfatase activity was linear with incubation time up to 4 h and with cell number up to 2 X 10(5)/ml. The apparent Km of amnion cell sulfatase for estrone sulfate was 5.5 microM. The product of hydrolysis, i.e. estrone, was metabolized in situ to 17 beta-estradiol in both amnion tissue and cells. The hydrolysis of estrone sulfate (and possibly other phenolic steroid sulfates present in amniotic fluid) by amnion cells may be important in providing biologically potent estrogens for in situ action.

Amnion↗
PubMed1985

Intermediate filament cytoskeleton of amnion epithelium and cultured amnion epithelial cells: expression of epidermal cytokeratins in cells of a simple epithelium.

Using immunofluorescence microscopy and two-dimensional gel electrophoresis, we compared the cytoskeletal proteins expressed by human amnion epithelium in situ, obtained from pregnancies of from 10-wk to birth, with the corresponding proteins from cultured amnion epithelial cells and cultures of cells from the amniotic fluid of 16 week pregnancies. Epithelia of week 16 fetuses already display tissue-specific patterns of cytokeratin polypeptides which are similar, although not identical, to those of the corresponding adult tissues. In the case of the simple amnion epithelium, a complex and characteristic complement of cytokeratin polypeptides of Mr 58,000 (No. 5), 56,000 (No. 6), 54,000 (No. 7), 52,500 (No. 8), 50,000 (No. 14), 46,000 (No. 17), 45,000 (No. 18), and 40,000 (No. 19) is present by week 10 of pregnancy and is essentially maintained until birth, with the addition of cytokeratin No. 4 (Mr 59,000) and the disappearance of No. 7 (Mr 54,000) at week 16 of pregnancy. In full-term placentae, the amnion epithelium displays two morphologically distinct regions, i.e., a simple and a stratified epithelium, both of which express the typical amnion cytokeratin polypeptides. However, in addition the stratified epithelium also synthesizes large amounts of special epidermal cytokeratins such as No. 1 (Mr 68,000), 10 (Mr 56,500), and 11 (Mr 56,000). In culture amnion epithelial cells obtained from either 16-wk pregnancies or full-term placentae will continue to synthesize the amnion-typical cytokeratin pattern, except for a loss of detection of component No. 4. This pattern is considerably different from the cytokeratins synthesized by cultures of cells from amniotic fluids (cytokeratins No. 7, 8, 18, and 19, sometimes with trace amounts of No. 17) and from several so-called "amnion epithelial cell lines." In addition, amnion epithelial cells in situ as well as amnion epithelial cell cultures appear to be heterogeneous in that they possess some cells that co-express cytokeratins and vimentin. These observations lead to several important conclusions: In contrast to the general concept of recent literature, positively charged cytokeratins of the group No. 4-6 can be synthesized in a simple, i.e., one-layered epithelium. The change from simple to stratified amnion epithelium does not require a cessation of synthesis of cytokeratins of the simple epithelium type, but in this case keratins characteristic of the terminally differentiated epidermis (No. 1, 10, and 11) are also synthesized.(ABSTRACT TRUNCATED AT 400 WORDS)

Amnion↗
PubMedDate not supplied

Site-specific augmentation of amnion cyclooxygenase-2 and decidua vera phospholipase-A2 expression in labor: possible contribution of mechanical stretch and interleukin-1 to amnion prostaglandin synthesis.

OBJECTIVE: To investigate a possible site-specific augmentation of prostaglandin (PG) synthesis in the fetal membranes during labor. METHODS: We used reverse transcriptase-polymerase chain reaction or Western blot analysis to evaluate the expression of cytosolic phospholipase A2 (cPLA2) and cyclooxygenase-1, -2 (COX-1, -2), in both the upper and lower parts of the amnion, chorion laeve, and decidua vera tissues from term pregnant women before (n = 8) and after labor (n = 24). Prostaglandin E2 (PGE2) secretion from amnion-derived WISH cells was assessed using enzyme-linked immunosorbent assay after stimulation by cyclic mechanical stretching and interleukin-1 (IL-1). RESULTS: The expression of cPLA2 and COX-1 and COX-2 mRNAs was detected in all samples examined. Western blot analysis revealed that COX-2 expression in the upper part of the amnion, chorion laeve, and decidua vera tissues after labor was 4.7-, 4.9-, and 3.7-fold higher than that before labor, respectively (P < .05 for all). The cPLA2 protein expression in the upper part of the amnion and chorion laeve tissues after labor was 14.0- and 8.8-fold higher than that before labor, respectively (P < .05 for both). Moreover, in specimens obtained after labor, the amnion COX-2 expression and the decidua vera cPLA2 expression in the lower part of the fetal membrane was 1.9- and 2.6-fold higher than the respective levels in the upper part (P < .05 for both). In an in vitro study, cyclic mechanical stretching significantly enhanced IL-1-augmented PGE2 secretion from WISH cells. CONCLUSION: In the lower part of the amnion and decidua vera tissues, adjacent to the dilating cervical canal, PG synthesis was upregulated site specifically after labor. Such enhancement of amnion PG synthesis might be regulated at least partly by IL-1 and cyclic distension.

Amnion↗
PubMed1999

Characterization of the amnion-derived AV3 cell line for use as a model for investigation of prostaglandin-cytokine interactions in human amnion.

Increased production of prostaglandins and cytokines by amnion, particularly prostaglandin (PG) E2, interleukin (IL)-6 and IL-8, is thought to be an important event in infection-associated preterm labour. We characterized the amnion-derived AV3 cell line to determine its appropriateness as a model for investigation of the regulation of amnion cytokine and PG production. Amnion-derived AV3 cells were treated with tumour necrosis factor-alpha (TNF-alpha, interleukin-1beta (IL-1beta), epidermal growth factor (EGF) and phorbol 12-myristate 13-acetate (PMA) and IL-6, IL-8 and prostaglandin production was determined by immunoassay. Production of IL-6 and IL-8 rose dramatically with all treatments. PGE2, but not PGF2alpha or 6-keto-PGF1alpha, biosynthesis was also increased in a concentration-dependent manner with all treatments. A rapid increase in PGHS-2 (but not PGHS-1) mRNA expression was observed in response to TNF-alpha and IL-1beta. We conclude that the AV3 cell line inflammatory response profile is similar to those observed in primary amnion and other amnion-derived cell lines, and is an appropriate model for human amnion.

Amnion↗
PubMed1999

Prostaglandin endoperoxide H synthase mRNA expression in the human amnion and decidua during pregnancy and in the amnion at preterm labour.

We have examined the expression of prostaglandin endoperoxide H synthase (PGHS) isoenzymes in the amnion and the decidua during gestation, and the abundance of PGHS mRNA in the amnion at idiopathic preterm labour. PGHS-1 and -2 mRNA abundance in the amnion, determined with ribonuclease protection assays, was significantly (P< 0.05) higher at term than earlier during pregnancy. In contrast, neither PGHS-1 and -2 mRNA values, nor PGHS-specific activity, measured with a cell-free assay, was different in the decidua at term as compared to earlier gestational ages. In individual term patients, PGHS-2 mRNA values in the amnion were positively correlated with PGHS-2 mRNA values in the chorion laeve. PGHS-1 and -2 mRNA abundance was higher (P < 0.05) in the amnion after idiopathic preterm labour than in the absence of labour at the same gestational age (28-35 weeks). Thus, PGHS-1 and -2 are induced in the amnion at term. Furthermore, amniotic PGHS-2 changes in co-ordination with PGHS-2 concentrations in the chorion laeve. PGHS is not induced in the decidua at term. Increased amniotic PGHS expression may contribute to the enhanced intrauterine prostaglandin synthesis before term labour. Both PGHS isoenzymes may participate in the increase of PGHS activity in the amnion at preterm birth.

Amnion↗
PubMedDate not supplied

Lactosylceramide-induced apoptosis in primary amnion cells and amnion-derived WISH cells.

Amnion apoptosis is part of a programmed process of fetal membrane remodeling leading to weakening and rupture. The apoptotic agent lactosylceramide is elevated in amniotic fluid of premature infants with rupture of membranes. We have shown that apoptosis in WISH cells, induced by staurosporine, cycloheximide, or actinomycin D, can be blocked by cyclooxygenase inhibitors, suggesting a relationship between prostaglandin production and apoptosis. Cyclic adenosine monophosphate (cAMP) is known to inhibit prostaglandin release in amnion and WISH cells. This study was undertaken to determine the apoptotic potential of lactosylceramide and the effect of cyclooxygenase inhibitors and cAMP activators on lactosylceramide-induced apoptosis in primary amnion and WISH cells. Primary amnion cells and WISH cells were incubated with lactosylceramide to determine apoptosis and prostaglandin E(2) (PGE(2)) release. Apoptosis was confirmed by agarose gel electrophoretic DNA fragmentation analysis, nuclear matrix protein (NMP), and nucleosome enzyme-linked immunosorbent assay. In some studies, cells were preincubated with cyclooxygenase inhibitors or cAMP activators. Lactosylceramide induced a 20-fold increase in NMP (measure of cell death) in both cell types. Apoptosis was confirmed by the studies listed in methods. Lactosylceramide increased PGE(2) release in parallel with apoptosis. Cyclooxygenase inhibitors as well as cAMP activators inhibited both PGE(2) release and apoptosis. Lactosylceramide-induced apoptosis in both amnion and WISH cells. Parallel PGE(2) release was demonstrated with apoptosis. Cyclooxygenase inhibitors and cAMP activators blocked both processes.

Amnion↗
PubMedDate not supplied

[Amnionic infusion therapy in conditions with low amnionic fluid levels].

INTRODUCTION: Amniotic fluid volume reduction can have serious consequences: prior to 24 gestational weeks hypoplasia of fetal lungs and later in pregnancy cord compression and fetal hypoxia as well as contractions of extremities. Diagnosis of oligohydramnios is made either after a subjective estimation of amniotic fluid reduction or if the biggest amniotic fluid pocket is less than 1 cm. Amnioinfusion is a procedure during which a crystalloid solution, most often saline, is instilled into the amniotic cavity substituting amniotic fluid. To estimate the efficacy and safety of amnioinsfusion using our results and literature review. MATERIAL AND METHODS: Up to 800 ml of sterile saline solution was instilled intraamniotically (10-15 ml/min) in cases where the amniotic fluid index was less than 10 and intraamniotic infection was excluded. After that, 1 g of Longaceph was given intraamniotically. Infusion was stopped immediately when 800 ml was instilled, if a subjective estimation showed that there was enough fluid or if contractions occurred. RESULTS: During a six-month period there were five amnioinfusions--four therapeutical and one diagnostic; in four cases the procedure was successful and in one preterm rupture of membranes occurred 20 hours after the procedure. The procedure was most often done in the first half of the third trimester and continuation of pregnancy in successful cases was between 4 and 5 weeks, with average fetal weight gain of about 1200 gr. No complications occurred in cases where pregnancy continued. CONCLUSION: In our preliminary study amnioinfusion led to prolongation of pregnancy in majority of cases providing better maturation of fetal lungs and higher birth weight, without any complications. Further studies are necessary to reach definite conclusions about the efficacy and safety of amnioinfusion.

Crystalloid Solutions↗