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 649 records · Page 36Linked to original sources
PubMedDate not supplied

[Consumption of intracellular hydrogen peroxide in epithelial human amnion cells].

The method for determination of intracellular oxidants content has been proposed. The method is based on the analysis of changes of 2,7-dichlorodihydrofluorescein oxidation. The theoretical model of hydrogen peroxide diffusion and its consumption in the cell and quantitative determination of hydrogen peroxide gradient through the cellular membrane has been built taking into account the experimental data. The coefficient for H2O2 permeability through the plasma membrane of human amnion cells is (2.1 +/- 0.1) x 10(-4) cm x c(-1).

Amnion↗
PubMed2006

[Repair of peripheral nerve defect by a scroll of amnion derivative compound with cultured autogenous Schwann cell in a rat model].

OBJECTIVE: To test a nerve bridge substitute for peripheral nerve repair by tissue-engineering approach. METHODS: An artificial nerve fabricated with a scroll of amnion derivative (ZQ membrane) and cultured autogenous Schwann cell was sutured to bridge sciatic nerve defect of 2.5 cm in length in rats. The specimens were assessed with tracking study, histology, electrophysiological technique, NF200, and synaptophysin-38 (SYP) immuno histochemical staining 3 months postoperatively. RESULTS: The regenerated nerve sprouted 3 months after the operation. The regenerated nerve fibers were plentiful and could grow into the recipient nerve and target muscle's motor end plate (MEP) areas to reinnervate target muscle, and reconstruct function of nerve-muscle junction. Functional recovery could reach to 40%-60% of normal control. Nerve-muscle conduction velocity (N-MCV) arrived at 21.77 +/- 1.15 m/s. CONCLUSIONS: A tissue engineering material fabricated with a scroll of ZQ membrane and cultured autologous Schwann cell may be a useful substitute for nerve repair.

Amnion↗
PubMed1991

Induction of cytochrome P450 isozymes in human amnion FL cells and its application to the biological detection of mutagens.

Using AHH, EROD, ECOD and APND as marker enzymes and 3-MC, beta-NF, NE and PB as inducers, inducible cytP450 IA and IIB gene expression was demonstrated in the human amnion FL cell line; these cells possess a broad spectrum of drug-metabolizing enzymes. Maximum induction was observed following co-treatment with 3-MC and NE. Both constitutive and induced AHH were proved to have the characteristics of cytP448-dependent mixed-function oxygenases. Induced cytP450 isozyme activity remained at a high level for 24-36 h after removal of the inducer. The induced FL cells were demonstrated to activate common promutagens/procarcinogens in UDS and ADPRT-mediated decrease of NAD content assay systems. This new design can be used as a simplified mutagen screening system: no supplemental liver microsomal activation system is needed.

Amnion↗
PubMed1990

Congenital rubella infection: escape of one monozygotic twin with two amnions, one chorion, and single placenta.

We report a 2 amnions, 1 chorion, single placenta, monozygotic identical twins, who were born by a mother with a subclinical rubella infection during the gestation; one twin had a congenital rubella infection, the other escaped from it. Both twins were premature and small for their gestational age at birth. They both had an intraventricular hemorrhage ascribed to prematurity. One had a strong positive rubella IgM antibody for more than 3 months and a persistent IgG antibody for more than 1 year. The other had a fading rubella IgG antibody within 3 months, and a negative IgM. The baby with the congenital infection of rubella did not have a defective appearance, but the auditory brain stem evoked potential test showed abnormal findings. In monozygotic identical twins, vessel communication usually exist and the escape of a twin from rubella is a rare condition; there have been only two such events reported in the English literature.

Amnion↗
PubMed1990

Structures of the asparagine-linked oligosaccharides of an alkaline phosphatase, kasahara isozyme, purified from FL amnion cells.

Asparagine-linked oligosaccharides were quantitatively released by hydrazinolysis from an alkaline phosphatase, Kasahara isozyme, which was purified from FL amnion cells. Almost all of the oligosaccharides (98%) were acidic components, all of which can be converted to neutral oligosaccharides upon sialidase digestion. Structural analysis of the oligosaccharides by sequential exoglycosidase digestion in combination with methylation analysis revealed that the alkaline phosphatase of FL cells contains sialylated mono-, bi-, tri-, and tetraantennary complex type sugar chains with the Gal beta 1----4GlcNAc beta 1---- outer chains. Some of the tetraantennary sugar chains contain a single Gal beta 1----4GlcNAc beta 1----3Gal beta 1----4GlcNAc beta 1---- outer chain on their Man alpha 1----6 arm. Both fucosylated and nonfucosylated trimannosyl cores were found in the sugar chains. However, it is of interest that the core portion of monoantennary oligosaccharide was not fucosylated and that of the tetraantennary oligosaccharide with a tetrasaccharide outer chain was completely fucosylated.

Alkaline Phosphatase↗
PubMed1989

Dexamethasone stimulates arachidonic acid conversion to prostaglandin E2 in human amnion cells.

The purpose of this investigation was to study the mechanism of stimulation of PGE2 output from human amnion epithelial cells by the synthetic glucocorticoid dexamethasone. Cells incubated in serum-free pseudo-amniotic fluid produced very low levels of PGE2, even when arachidonic acid (1 microM) was present. Pretreatment of cells with dexamethasone (50 nM) for 21 h increased the PGE2 output 6- to 7-fold in 2-h incubations only in the presence of arachidonic acid. The RNA synthesis inhibitor, actinomycin D (1 microgram/ml), and the protein synthesis inhibitor, cycloheximide (40 micrograms/ml), each blocked dexamethasone-stimulated arachidonic acid conversion to PGE2. The time course of these events suggests that dexamethasone first initiates RNA synthesis. Acetylsalicylic acid, a specific and irreversible blocker of prostaglandin endoperoxide H synthase (cyclooxygenase), was used to determine whether dexamethasone could stimulate new enzyme synthesis. Cells treated first with acetylsalicylic acid (30 min) then dexamethasone (22 h) produced as much PGE2 in response to 1 microM arachidonate as did cells exposed to dexamethasone only. Exposing cells to acetylsalicylic acid after dexamethasone completely eliminated PGE2 output. These data suggest that dexamethasone stimulates the synthesis of prostaglandin endoperoxide H synthase.

Amnion↗
PubMed1989

Suppression by cathepsin L inhibitors of the invasion of amnion membranes by murine cancer cells.

Cysteine proteinases, particularly cathepsins B and L, have been strongly implicated in fostering metastasis in mice. In this work four different inhibitors of cysteine proteinases have been shown to inhibit the invasion of the human amnion by murine melanoma and mammary carcinoma cells in vitro. Two of the inhibitors are synthetic peptides [ZPhePheCHN2 (benzyloxycarbonyl-L-phenylalanyl-L-phenylalanyldiazomethane) and ZPheAlaCH2F [3-(N-benzyloxycarbonylphenylalanylamido)-DL-1-fluoro-2-butanone]] and two are thiol protease inhibitors (TPIn, TPId) isolated from the skeletal muscle of the hind limbs of normal and dystrophic mice, respectively. The inhibitors (ZPhePheCHN2, TPId), with apparent selectivity for cathepsin L, blocked invasion as effectively as inhibitors (ZPheAlaCH2F, TPIn) effective on both cathepsins. The data reveal that in these cell lines the cysteine proteinases contribute significantly to the invasive capacity of the cells, but to a lesser extent than do the metalloproteinases. We suggest that the cysteine proteinases facilitate the action of metalloproteinases (collagenase, gelatinase, and stromelysin), possibly by activating them, by inactivating the tissue inhibitor of metalloproteinases, and/or by making basement membrane matrix more accessible.

Amnion↗
PubMed1987

[Cytopathogenic action of intact and antibiotic-altered populations of Bordetella pertussis on a human amnion cell culture].

Cytopathogenic and adhesive action of intact B. pertussis population and population changed under the effect of antibiotics was studied comparatively. It was shown that the level and character of the changes in the cell culture of line FL human amnion depended on the antibiotic used in the experiments. Populations of B. pertussis changed under the effect of tetracycline had the highest cytopathogenic and adhesive activity, while the activity of the population changed under the effect of erythromycin was the least. The decrease in the cytopathogenic and adhesive activity of B. pertussis changed under the effect of erythromycin correlated with lowering of the toxicity and the loss of the main agglutinogenic factors of the surface of the bacteria cell wall. The increase in the toxicity of the population changed under the effect of tetracycline was accompanied by changes in the cytopathogenic and adhesive properties of the culture.

Amnion↗
PubMed1985

[Comparison of the effects of taurine and magnesium on electrical characteristics of artificial and natural membranes. IV. Effects on different components of the paracellular and cellular conductances of the human amnion].

The ionic conductance, Gt, through the isolated human amnion is the sum of several conductances: Gt = Gp + Gc + Gs. Gp, the paracellular conductance is: Gp = Gj + Gjc (Gj is due to the intercellular channel and Gjc due to the electrical coupling factor); Gc, the cellular conductance is: Gc = Gc1. Gc2/Gc1 + Gc2 with Gc1 = GAC + GAC1 and Gc2 = GM + GM1, GAC and GM being the dependent conductances on amniotic cavity (AC) and maternal (M) sides; GAC1 and GM1 being the leak conductances on AC and M. Gp and Gc are due to epithelial cell layer and Gs (conductance in a series) is due to the other layers. The utilization of metabolic inhibitors (ouabain, amiloride, DNP) allows one to split up Gt into various components. In this study, the action of magnesium and taurine (TA) was studied on the various conductances in Hanks' solution modified by metabolic inhibitors. In Hanks' solution: + ouabain, Mg and TA increased GAC1 and GM1; - + amiloride, Mg increased GAC and GM but TA had no effect; - + ouabain + amiloride, Mg and TA increased GK. In this way, Mg appears to have an action on the ATPase and on the regulation of the Na+ and K+ channels, but TA has no effect on the ATPase but TA appears to govern the viability of the Na+ and K+ channels. Moreover, TA and Mg have a compensatory effect on GAC1, GM1 and Gjc in Hanks' solution, but their actions are not cumulative.

Adenosine Triphosphatases↗
PubMed1985

Mechanism of interferon action: inhibition of vesicular stomatitis virus replication in human amnion U cells by cloned human gamma-interferon. I. Effect on early and late stages of the viral multiplication cycle.

The molecular basis of the inhibition of vesicular stomatitis virus (VSV) replication by pure recombinant gamma-interferon (IFN-gamma) in human amnion U cells was examined. A saturating concentration of IFN-gamma induced, at maximum, about a two log10 reduction in infectious VSV yield. The kinetics of induction of the antiviral activity by IFN-gamma were first order over the period of about 6-18 h, following a lag of about 3 h, after treatment with a saturating concentration of IFN-gamma. The relationship of the inhibition in VSV infectivity to the early and late events of the VSV multiplication cycle was investigated. IFN-gamma treatment had no detectable effect on the adsorption and penetration of VSV virions or on their uncoating to yield viral nucleocapsids. The polypeptides of adsorbed or uncoated VSV particles were neither preferentially degraded nor detectably altered in IFN-gamma-treated U cells, as compared to untreated U cells. Progeny virions isolated from IFN-gamma-treated U cells, although greatly reduced in number, were found to be equally as infectious as those isolated from untreated U cells. Progeny virions from IFN-gamma-treated cells also possessed the same composition of viral proteins as was observed for virions from untreated cells. These results suggest that conditions of IFN-gamma treatment sufficient to reduce the yield of infectious VSV progeny 100-fold do not detectably affect either the early or the late stages of the VSV multiplication cycle.

Amnion↗
PubMed1986

[Cellular ultrastructure of the meningococcus when incubated in a continuous culture of human FL-line amnion].

Some details of the ultrastructure of several meningococcal strains having had contacts with cells in continuous human amnion cell culture FL for 6 hours to 2 days have been defined with greater precision by means of electron microscopy. The study has shown that the contact of meningococci with the tissue culture is accompanied by the appearance of meningococcal forms with the defective cell wall, similar to L-forms: spheroplast, protoplast, gigantic cells and microcells, as well as budding variants. The meningococcal variants with the defective cell wall, appearing in the cell culture, and the forms occurring (in different proportions) in "ripe" meningococcal populations developing in the culture media for a long time and isolated from a human body have been found to have no essential differences in their fine structure. These data indicate that any external influences (meningococci are highly sensitive to such influences) produce sufficiently rapid changes, similar to L-transformation, in the fine structure of these microorganisms.

Amnion↗
PubMed1986

[Electron microscopic study of the cytopathogenic action of meningococci in a continuous human amnion cell culture].

The electron-microscopic study of the interaction of meningococci with continuous human amnion cell culture F1 has revealed that this process comprises 3 stages. The study has shown that, following the adhesion of meningococci to the surface of cells F1, these cells are invaded by individual coccal forms of meningococci. In response to infection vacuoles appear in the cytoplasm of the cells. Meningococci are either phagocytosed inside these vacuoles, or their release into the intercellular space and the death of the infected by meningococci are observed. When the cells are infected by cytopathogenic strains, the infectious process results in the appearance of degenerative changes in the cells.

Amnion↗
PubMed1988

Relationship between magnesium, carcinogenic metals and ionic permeability of the human amnion.

The effects of the well established carcinogenic metals or metalloids (As, Be, Cr, Ni), hypothetically carcinogenic but well-established cocarcinogenic metals (Cd, Pb, Co) and weak co-carcinogenic metals (Al, Cu, Fe, Zn) and the antagonism between Mg and these metals were studied on the ionic transfer through the isolated human amnion. The ionic transfer is estimated by the measure of the membrane potential (delta psi), the cationic number transference t+ and the ionic fluxes (F1, F2). All carcinogenic metals increase delta psi (+) and reduce t+, F1 and F2. Mg has an opposite action with regard to Cd, Pb and Ni, but may act as a co-carcinogenic agent by increasing the effects of Al, Cu and Zn.

Aluminum↗
PubMed1988

Towards establishing comprehensive databases of cellular proteins from transformed human epithelial amnion cells (AMA) and normal peripheral blood mononuclear cells.

Databases of protein information derived from the analysis of two-dimensional gels have been established from transformed human amnion cells (AMA) and peripheral blood mononuclear cells (PBMCs). A total of 1781 [35S]methionine-labeled AMA proteins (1274 IEF, 537 NEPHGE) and a total of 1311 proteins from PBMC (948 IEF, 363 NEPHGE) were resolved and recorded using computerized (PDQ-SCAN and PDQUEST softwares) two-dimensional gel electrophoresis. AMA and PBMC proteins (total, 454: 301 IEF, 153 NEPHGE) were matched both manually and by the computer. Information entered in the AMA database (in most cases for some major proteins) includes: molecular weight, protein name, HeLa protein catalogue number, mouse protein catalogue number, nuclear proteins, phosphorylated proteins, distribution of proteins in Triton X-100 supernatants and cytoskeletons, proliferation- and transformation-sensitive proteins, cell cycle-specific proteins, mitochondrial proteins, proteins matched in normal human embryonal lung MRC-5 fibroblasts and PBMC cells, heat shock proteins, proteins affected by interferons, cytoskeletal proteins, and the presence of antibody against protein in human sera. Additional information has been entered for the cell cycle-regulated and DNA replication protein cyclin (PCNA). Information entered in the PBMC database includes molecular weight and potential markers for sorted populations of lymphocyte subtypes. For those proteins that have been matched to AMA proteins, information contained in some entries may be transferred from the AMA database.

Amnion↗
PubMed1986

Vaginoplasty using amnion.

Fifteen patients with various developmental and acquired abnormalities of the vagina were treated by the application of human amnion over a mold after surgical dissection of a space for the new vagina or enlargement of an existing but strictured one. Excellent results were achieved in cases of complete and partial vaginal agenesis, and there was improvement in all of the patients with vaginal strictures.

Adolescent↗
PubMed1979

Vaginal epithelialization with human amnion.

Human amnion is a readily available and inexpensive allograft with low antigenicity, high antimicrobial potential, and the ability to foster epithelialization. It has been used to reconstruct the vagina in 2 patients following vaginectomy for diffuse carcinoma in situ (CIS) and in 1 patient following severe, corrosive, vulvovaginal burns. It was also used to construct the vagina in 1 patient with müllerian agenesis. In all 4 cases, epithelialization was complete within 8 weeks.

Adolescent↗
PubMed1983

Mechanism of interferon action: inhibition of vesicular stomatitis virus replication in human amnion U cells by cloned human leukocyte interferon. I. Effect on early and late stages of the viral multiplication cycle.

The kinetics of induction in human amnion U cells of the antiviral activity against vesicular stomatitis virus (VSV) produced by a single molecularly cloned subspecies of human leukocyte interferon (IFN-alpha A) were examined. IFN-alpha A-induced inhibition was found to be biphasic over a period of 24 h with the major extent of VSV inhibition occurring within the first 6 h of IFN treatment. The relationship of this major phase of inhibition to the early and late events of the VSV multiplication cycle was investigated. IFN-alpha A treatment had no detectable effect on the adsorption and penetration of VSV virions or on their uncoating to yield viral nucleocapsids. The polypeptides of adsorbed or uncoated VSV particles were neither preferentially degraded nor detectably altered in IFN-treated cells, as compared to untreated cells. Progeny virions released from IFN-treated cells, although greatly reduced in number, were found to be equally as infectious as those released from untreated cells. Progeny virions from IFN-treated cells also had a normal complement of VSV proteins in the same ratios as were seen in virions from untreated cells; specifically, IFN treatment produced no reduction in the incorporation of G or M protein into assembled virions. These results suggest that conditions of IFN treatment sufficient to reduce the yield of infectious VSV progeny greater than 99% do not detectably affect either the early or the late stages of the VSV multiplication cycle.

Amnion↗
PubMed1983

Mechanism of interferon action: inhibition of vesicular stomatitis virus replication in human amnion U cells by cloned human leukocyte interferon. II. Effect on viral macromolecular synthesis.

The effects of a single molecularly cloned subspecies of human leukocyte interferon (IFN-alpha A) on vesicular stomatitis virus (VSV) macromolecular synthesis in human amnion U cells were examined. IFN-alpha A was found to uniformly inhibit VSV protein synthesis to an extent sufficient to account for the overall inhibition of viral infectivity. IFN-alpha A treatment also prevented the shutoff of cellular protein synthesis observed in untreated, VSV-infected U cells. By use of the VSV mutant tsG41, which is competent in RNA transcription but defective in RNA replication at 40 degrees C, it was shown that IFN did not significantly inhibit the accumulation of VSV primary transcripts, although the in vivo translation of primary viral transcripts was greatly impaired as a function of IFN treatment. Thus, the major, and possibly only, effect of IFN-alpha A on VSV replication was translation inhibition. Analysis of RNA, separated by agarose gel electrophoresis after denaturation with glyoxal, with cDNA probes to individual VSV mRNAs, did not reveal any detectable difference in the structural integrity of VSV mRNA isolated from IFN-treated as compared to untreated cells. Likewise, in vitro protein synthesis did not reveal any major difference in the functional integrity of VSV mRNA isolated from IFN-treated as compared to untreated U cells. Viral mRNA isolated from either wild type or tsG41-infected U cells treated with IFN was translated only slightly less efficiently in vitro than viral mRNA from untreated cells. Thus, the principal cause of the IFN-induced inhibition of viral protein synthesis observed in vivo appears to be an alteration of a component of the translational machinery other than the mRNA template.

Amnion↗