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PubMed1982

Specific cells of human amnion selectively localize prolactin.

The presence of PRL in high concentration in human amniotic fluid has been related to changes in water transport across amnion but not chorion leave. The cellular composition of human amniotic epithelium has been reported to include at least two structurally distinct cell types, known as light cells and dark cells, that differ in their ability to transport large molecules. In the present study, human amnion obtained from term cesarean section was evaluated through the use of autoradiography as to its ability to localize hormones of similar and variant molecular sizes. Amniotic epithelium exposed to [125I]human PRL, [125I]human Gh, [125I]human beta-endorphin, [125I]bovine FSH, and sodium 125I alone was found to display a selectivity in its ability to localize [125I]human PRL only. Furthermore, the selective localization of [125I]human PRL was found to be specific to the light cells, because dark cells failed to localize any of the other tracers used. These data provide additional evidence in support of the recently proposed concept that term human amniotic epithelium consists of at least two functionally distinct cell types. Furthermore, the high levels of PRL in amniotic fluid may have a specific physiologic role in the amniotic membrane during human gestation.

Amnion↗
PubMed1995

A comparative study of progesterone synthesis by term human fetal amnion and chorion.

Activity of 3 beta-hydroxysteroid dehydrogenase-5, 4-en isomerase was investigated with [7n-3H] pregnenolone as substrate in the homogenates of amnion and chorion collected from women (n = 6, age 20-34 years) after spontaneous labour at term (37-40 weeks gestation) from uncomplicated pregnancies. Controls were heat-denatured homogenates instead of fresh homogenates. Reverse-isotope dilution analysis gave positive identification of [3H] progesterone in all incubations of viable tissues. This metabolite was not evident in the controls. The extent of enzymic conversion of chorion, 1.4-31.1% was consistently higher than that of the amnion, 0.66-1.7%. The results show that the human fetal membranes can be a source of progesterone during pregnancy. The metabolic capability may have physiological significance in the induction and progression of labour to parturition.

Amnion↗
PubMed1994

Regulation of prostaglandin endoperoxide H synthase by glucocorticoids and activators of protein kinase C in the human amnion.

Since glucocorticoids decrease and protein kinase C (PKC) activators increase amniotic PGE2 production, the possibility that they regulate the activity of prostaglandin endoperoxide H synthase (PGHS), the rate-limiting enzyme of prostaglandin synthesis from arachidonate, was investigated. Glucocorticoids inhibited the production of PGE2 from exogenous arachidonate specifically and in a concentration dependent fashion. Furthermore, cortisol decreased PGHS activity and the amount of PGHS protein in amnion microsomes, and reduced the rate of recovery of PGHS after acetylsalicylic acid (ASA) pretreatment. Actinomycin D blocked the inhibition of PGHS recovery by cortisol, but did not suppress the spontaneous recovery of the enzyme, indicating that the glucocorticoid induced a post-transcriptional inhibitor of PGHS synthesis. PKC-activating phorbol esters, such as 12-tetradecanoyl phorbol 13-acetate (TPA) increased the synthesis of PGE2 from exogenous arachidonate, also in a specific and concentration dependent manner. PGHS recovery after ASA treatment was enhanced by TPA. PGHS activity and protein concentrations were increased by phorbol ester treatment; however, this was apparent only in tissues in which the concentrations of PGHS were initially low. These results show that the synthesis of PGHS is positively and negatively regulated in the human amnion by PKC and glucocorticoids, respectively, and suggest that effectors using these pathways may regulate the enzyme in vivo.

Amnion↗
PubMed1998

Tumour necrosis factor-alpha stimulates increased expression of prostaglandin endoperoxide H synthase Type 2 mRNA in amnion-derived WISH cells.

We have evaluated the mechanism by which tumour necrosis factor-alpha (TNF-alpha) induces increased prostaglandin (PG) biosynthesis in amnion-derived WISH cells. WISH cells were treated with 50 ng/ml TNF-alpha or vehicle for 0-24 h. PGE2 production was stimulated by TNF-alpha within 2 h and continued to accumulate for at least 24 h. Increased prostaglandin endoperoxide H synthase (PGHS)-2 mRNA expression was evident within 30 min and was highest by 1 h, returning to unstimulated levels by 2 h. The PGHS-2 mRNA was re-induced at 8 h and was also elevated at 16 h. Immunoreactive PGHS-2 protein was nearly undetectable in control cells. However, within 30 min of TNF-alpha treatment, PGHS-2 protein was elevated and was induced for at least 16 h suggesting rapid production of both the PGHS-2 mRNA and protein. Transcription run-on assays indicated that the initial increase in the PGHS-2 mRNA was due to a 20-fold increase in the rate of transcription. The PGHS-2 mRNA decayed with an apparent half-life of 1 h in TNF-alpha-stimulated WISH cells. Induction of PGHS-2 expression proceeded in the presence of 10 microg/ml cycloheximide which agrees with the classification of PGHS-2 as an immediate early gene. These results indicate that a bi-phasic induction of the PGHS-2 mRNA is due, in part, to an initial transcriptional activation which results in rapid and continued synthesis of the PGHS-2 protein. This may be a unique characteristic of amnion cells which may be partially responsible for increased PG concentrations in the amniotic fluid during infection-associated preterm labour.

Amnion↗
PubMed2000

Second- and third-trimester ultrasound evaluation of chorionicity and amnionicity in twin pregnancy. A simple algorithm.

OBJECTIVE: To develop a simple and systematic algorithm to determine chorionicity and amnionicity in the second and third trimester by ultrasound. STUDY DESIGN: The algorithm was constructed based upon years of experience in examining multifetal pregnancies and by adopting the different sonographic signs suggested in the literature. RESULTS: The following parameters were used to construct the algorithm: sexing of the fetuses, placental location, and origin, thickness and number of layers of the membranes. CONCLUSION: The flow chart developed is simple to use and embodies all possible sonographic parameters to help determine chorionicity and amnionicity in the second and third trimester.

Algorithms↗
PubMed1975

[The amniotic infection syndrome and premature rupture of the amnion. Manifest and threatening unspecific intra-uterine infections of the last third of pregnancy (author's transl)].

In the last third of pregnancy the unspecific bacterial diseases of placenta, umbilical cord and membranes differ from those in earlier months [154; 155; 85]. There is a parallel change in the localization of fetal organs affected. Pathologic anatomical clarification of this led to the conceptual definition of the rare extra-amnial placental-fetal path of infection on the one hand and of primary intra-amnial infection with secondary chorion-amnionitis on the other hand and to identification of the amniotic infection syndrome as a typical entity at the end of pregnancy [19]. While the amnionic sac is closed, unspecific fetal inflammation is rare. Generally this happens only after rupture of the membranes. Since the amniotic infection syndrome often produces only minor clinical symptoms and since fetal infection probably starts early, one searched for means of assessing the risk of infection independently from symptoms. In comparative series of investigations of pregnancies with and without premature rupture of the membranes, cases of neonatal death from infection were preceded by signs of inflammation in placenta, umbilical cord and membranes. Together with the fetal and maternal infections they depended on the length of time between rupture and the onset of labor. pns. The data now available give a clear picture of the development of the inflammatory processes in mature and premature children and suffice for the assessment of fetal and maternal risks.

Abortion, Septic↗
PubMed2000

[Pharmacokinetic analysis of alpha- and beta-adrenoreceptors in the chick embryo amnion].

Following a stimulation with acetylcholine, the beta-adrenergic agonists adrenaline (A), noradrenaline (NA), isoproterenol (Iso) and salbutamol (Sal) induced a concentration-dependent decrease in the tone and (or) rate of amnion contraction with EC50 ISO < NA << A < Sal. Metaprolol, a specific beta 1-antagonist, induced a rightward shift in the dose-response curves of Iso, NA and A, whereas beta-antagonist butoxamine was ineffective. pA2 values for beta-antagonists were propranolol 8.3, metoprolol 7.0, butoxamine 5.6. EC50 values of alpha-adrenergic agonists form a sequence: clonidine < NA << methoxamine < phenylephrine. Specific alpha-antagonists yohimbine and idazoxan were found to antagonise competitively the effects of NA. The data obtained characterize the adrenergic receptors mediating stimulation of amniotic contractile activity as alpha 2-adrenergic receptors. Inhibition of contractile receptors in amnion is mainly mediated by beta 1-adrenergic receptor activation.

Adrenergic Agonists↗
PubMed2001

[Use of amnion in the treatment of anterior segment diseases of the eye].

PURPOSE: The aim of this study is to present the results of treating the anterior segment of the eye with amnion membrane transplantation (AMT). MATERIALS AND METHODS: 16 patients were treated with amnion membrane transplantation because of: pemphigoid ocularis, combustio chaemica, ulcus corneae, keratopathia bullosa, descemetocele, symblepharon, graft disease. Histopathological investigations were performed by the use of impression cytology. RESULTS: In 4 patients we obtained only temporary improvement. In 12 patients the treatment was successful with complete reepithelialization of the cornea and the conjunctiva. The impression cytology study showed an intensive regeneration of the corneal and conjunctival epithelium.

Adult↗
PubMed2005

[Clinical study in combining application of mitomycin and amnion transplantation together with pterygium resection].

PURPOSE: The aim of this study was to evaluate the effectiveness and safety of combining application of mitomycin and/or amnion transplantation when carrying out pterygium resection. METHODS: Pterygium resection, mitomycin application and amniotic membrane transplantation were carried out in three combinations: Pterygium resection plus local application of mitomycin C (MMC group, n=114), Pterygium resection plus amnion transplantation (AMT group, n=119) and Pterygium resection plus mitomycin C application and amniotic membrane transplantation (combined group, n=127). The patients were followed up for 6-18 months. The healing time, the cases of recurrence and complication were recorded and analysed. RESULTS: As for the recurrence rate, it seems that the rate in the combination group (0.79%) was smaller than that in other two groups (5.26% and 6.72%), but the difference between them was insignificant. The patients in the AMT group and in the combined group recovered faster than those in the MMC group. The healing time of the wound in the MMC group (10 +/- 2.8)d was longer than that in the AMT group (4.8 +/- 2.1) d, (P < 0.001) and that in the combined group (5.0 +/- 2.3)d, (P < 0.001). The complication rate of defect at corneal epithelium in the MMC group (10.5%) was significantly higher than that in the AMT group (0%; x2 = 13.2, P < 0.001) and that in the combined group (0.8%; x2 = 211.2, P < 0.001). The hyperemia of conjunctiva and irritation symptoms in eye in the MMC group were more serious than those in other two groups (P < 0.001). CONCLUSION: Combining application of MMC and AMT together with Pterygium resection decrease the rate of complications, eases the irritation symptoms, facilitates the recovery from the operation and may decrease the recurrence of the disease.

Aged↗
PubMed1991

Effects of amnion and live yeast cell derivative on second-intention healing in horses.

Equine amnion and live yeast cell derivative were evaluated as a biological dressing and as a topical wound medicament respectively, in the treatment of granulating wounds of the distal portion of the limbs of horses. Wounds measuring 2.5 x 2.5 cm were created on the dorsomedial aspect of the metacarpal and metatarsal region of all 4 limbs of 9 horses. Each wound was assigned randomly to 1 of 3 treatment groups: group C, treated with a nonadherent bandage as a control; group A, treated with amnion beneath a nonadherent bandage; and group L, treated with live yeast cell derivative beneath a nonadherent bandage. Rates of contraction and epithelialization were not significantly different among groups. Percentage of epithelialization for group A was significantly greater throughout the study than for the other groups. Number of days to complete healing was significantly less in group A and significantly greater in group L than in group C. Incidence and severity of exuberant granulation tissue were significantly less in group A than in the other 2 groups. Group L had more frequent and severe cases of exuberant granulation tissue than the other 2 groups.

Amnion↗
PubMed1990

Mono-sulfated glycosphingolipids of human amnion.

Two mono-sulfated glycosphingolipids were isolated from the human amnion. By carbohydrate analysis and acid hydrolysis, the structure of these glycolipids are proposed to be galactosylsulfatide (SM4s) and lactosylsulfatide (SM3). The major fatty acids of SM4s and SM3 were C16:0. The yields of SM4s and SM3 from the amnion were about 340 and 110 pmol/g wet wt, respectively.

Amnion↗
PubMedDate not supplied

[Catecholamines and DOPA in the amniotic fluid and amnion of the chick embryo].

Identification and quantitative fluorimetric assay have been made on the content of DOPA, dopamine, noradrenaline and adrenaline in the amniotic fluid and amnion of the developing chick embryos. Significant increase in the content of DOPA, noradrenaline and adrenaline in the amniotic fluid was observed between the 6th and the 13th days of incubation; dopamine content sharply decreases at the 13th day. The content on amines in the amnion tissue remained essentially constant throughout the investigated period. The role of catecholamine in amniotic fluid in regulation of contractile activity of amniotic membrane in the developing chick embryo is discussed.

Amnion↗
PubMed1990

[Personal experiences with covering burns in children with amnion].

The different methods of local treatment of burns are still controversial. Aims of good local are the therapy prevention of fluid loss, loss of proteins, electrolytes, heat and energy, prevention eg. reduction of wound infections, preservation and acceleration of regeneration of remained own skin, influence on good formation of scars eg. preparing of high value as possible transplant-ground for eventual necessary skin transplantation. Experience in covering juvenile burn-injuries with lyophilized Human-Amnion were gathered in our department for more than 15 years. The treatment of patients with this "biological bandage" and results were demonstrated. In our opinion the method of primary amnion covering of juvenile burn-injuries is superior to other procedures.

Amnion↗
PubMed1989

Effect of lipid and protein fractions from fetal pulmonary surfactant on prostaglandin E production by a human amnion cell line.

Discs of amnion and choriodecidua prepared from women delivered at term were incubated with and without surfactant prepared from human amniotic fluid and the output of prostaglandin E (PGE) was estimated by radioimmunoassay. Surfactant stimulated the release of PGE in both tissues. The stimulatory effect was characterized further using cultured human amnion cells. The effect was dose- and time-dependent and required for full expression both protein and lipid components of surfactant. Arachidonate constituted about 3.5% of the fatty acids of fetal surfactant phospholipids. These findings suggest that surfactant is an important source of arachidonate for intrauterine PG synthesis.

Amnion↗
PubMed1989

[Selective inducing ability of DL-111-1T towards mixed function oxidase in female rat liver and human amnion fluid cell].

Following pretreatment of adult female rats with contragestational agent 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazol (DL 111-1T) 20 mg/kg.d for 2 consecutive days, the hepatic microsomal MFO and UDPGT activities were induced to a constant level, being characteristic of arylhydrocarbon type of induction. Coincubation of human amnion FL cell with 0.1 mumol/L of DL-111-1T for 24 h produced a 4.5-fold induction of AHH activity of the cell. This inducing ability was 3 times that of PB, but 1/2 that of 3-MC. According to these observations, DL-111-1T may also be considered as a polycyclic arylhydrocarbon type inducer toward human amnion FL cell's MFO which contains mainly of cytochrome P-448. UDS test showed that DL-111-1T itself could not induce UDS of FL cell.

Abortifacient Agents↗
PubMed1989

[Scleroplasty results in progressive myopathy with the use of allogeneic amnion].

The paper analyses results after surgical intervention in 105 patients with progressive myopia (113 eyes), using allogeneic amnion for the period of two last years. Myopia remained stable in 62 eyes, and among the fellow non-operated eyes--only in 8. Visual acuity with correction rose in 50 and remained unchanged in 54 eyes. This can be regarded as a positive result when it concerns progressive myopia. Allogeneic amnion is an accessible, reliable, simple in working up material for scleroplasty. The operation described can be made under local anesthesia both in adults and children.

Adolescent↗
PubMed1988

Study of the antagonism between zinc and various embryonic toxics on human amnion permeability. I. Zinc and cadmium.

The effects of Cd and Zn have been studied on the ionic permeation of the isolated human amnion, expressed by the measure of the transamniotic conductance Gt and the flux ratio (mother-fetus/fetus-mother: F1/F2). Cd has no action on Gt on the fetal side and decreases Gt on the maternal side by a screening effect. Zn acts on the two faces by a screening-binding effect. The ratio F1/F2 remains constant with Zn concentration, but decreases with Cd and becomes less than 1 at 5 mmol/l of Cd. F1/F2 decreases with the duration of the administration of Cd. Zn has the opposite effect of Cd on the ionic transfer and has a stabilizing action on the amnion. Moreover, Zn may antagonize the noxious effect of Cd on the maternal side.

Amnion↗
PubMed1985

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

The effects of recombinant human gamma-interferon (IFN-gamma) on vesicular stomatitis virus (VSV) macromolecular synthesis in human amnion U cells were examined. Saturating concentrations of IFN-gamma caused only a 3 to 5-fold reduction of viral protein synthesis in wild-type VSV-infected cells, an extent insufficient to account for the 100-fold inhibition of viral infectivity. 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 the apparent IFN-induced inhibition of viral protein synthesis was likely due to a reduction in the synthesis of primary transcripts in IFN-gamma-treated U cells. Dot blot hybridization analysis revealed that saturating concentrations of IFN-gamma reduced both primary (measured with mutant tsG41-infected U cells) and total (measured with wild-type-infected U cells) viral RNA synthesis by about 4-fold, an extent of inhibition comparable to the observed reduction in viral protein synthesis. Analysis of RNA, fractionated 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-gamma treated as compared to untreated U cells. These results suggest that IFN-gamma treatment causes a small reduction in the efficiency of transcript formation catalyzed by input parental virions. However, the results also indicate that the principal cause of the IFN-gamma-induced inhibition of VSV replication in U cells is the alteration of a step in replication other than viral macromolecular synthesis. This implies that the molecular mechanism of viral inhibition by IFN-gamma is fundamentally different from that of IFN-alpha in human amnion U cells.

Amnion↗