Amnion cells

Fey SJ, Larsen PM, Cells JE. (1983) Evidence for coordinated phosphorylation of keratins and vimentin during mitosis in transformed human amnion cells. Phosphate turnover of modified proteins. FEBS Lett 157, 165-9. 

Cells, J E and Madsen, P (1986) Increased cyclin/PCNA antigen staining of non S-phase transformed human amnion cells engaged m nucleotide excision DNA repair FEBS Lett 209, 277—283. 

The addition of urea to tissue cultures of human amnion cells has been found to induce urease formation (83). Urease from the seed of the legume Glyciridia maculata has been purified (84) and found to be advantageous for commercial purposes. This enzyme was reported to have no activity at 30° and below but to be active at 50°-60° ... 

Results have been pooled from several sources (Firket, 1965 Cleaver, 1967 Lipkin, 1971 Puck, 1972) to give a general range of data which should be compared to the results for human amnion cells (Sisken and Morasca, 1965) and mouse L5178Y cells (Defendi and Manson, 1963). As the duration of mitosis is short and not always reported, where known it has been shared between /Gl and tG2. T is the total cell generation time /Gl, /S and /G2 are the durations of the Gl, S and G2-phases, respectively. (See Fig. 10.1 for a diagrammatic representation of the cell cycle.)... 

Table 4. Toxicity of Platinum Polymers on Human Amnion Cells In Culture. (WISH)...

Monolayer cultures of WISH (human amnion) cells were treated with the Indicated concentrations of each polymer. Toxic effects were recorded at the end of 24 hours. 4 = lOOt cell destruction, 3 = 751,... 

Celis, J. E., Madsen, P., Ryazanov, A. G. (1990). Increased phosphorylation of elongation factor 2 during mitosis in transformed human amnion cells correlates with a decreased rate of protein synthesis. Proc. Natl. Acad. Sci. USA 87,4231-4235. 

The PLC-Dependent Mechanisms. The PLC-dependent mechanisms, in contrast to the PKA-dependent signaling system, are important regulators of basal PG production. PG synthesis is associated with activation of PLC and subsequent production of diacylglycerol, inositol-1,4,5-triphosphate, release of Ca ", and Ca -induced activation of PKC (1). Stimulation of PKC by phorbol 12,13-dibutyrate activates PGF secretion by bovine endometrial cells (3). In hamster ovarian cells and rabbit amnion cells, OT activated production of both PGE and PLC, which suggests that the PLC-dependent signaling pathway not only controls basal PG secretion, but also mediates the effect of OT on this process (9). 

The MAPK-Dependent Mechanisms. The MAPK-depen-dent mechanisms can be activated by PKC which phosphory-lates the Raf protein, an important kinase of the MARK cascade (1). PLC and PKC can stimulate PGF release by bovine endometrial cells (3), rabbit amnion cells, and hamster ovary cells (9) via the MAPK-dependent pathway. In porcine granulosa cells, the MAPK blocker PD98059 did not affect basal PGF and PGE secretion. Nevertheless, GH, a stimulator of both PGF and PGE, increased the accumulation of MAPK (ERK1,2) in porcine granulosa cells, whereas the MAPK inhibitor PD98059 prevented a stimulatory action of GH on the release of these PG (12). Thus, MAPK can be a mediator of GH action on PG release, but the involvement of MAPK in basal PG secretion should not be excluded. 

Some of the chromosomal regions boxmd to the nuclear membrane may be the sites where DNA synthesis is initiated (Comings and Kakefuda, 1968). When the site of incorporation of radioactive thymidine was studied at the start of the S phase in synchronized human amnion cell cultures, the label was found to be localized at the nuclear membranes (Comings and Kakefuda, 1968), suggesting that the chromosomal sites at which DNA synthesis was initiated were attached to the nuclear membrane. It was... 

Dry with a thin strip of Whatmann 3MM paper and apply the sample (up to 50 1 in lysis solution, in this case about one million hot trichloracetic acid-precipitable counts of [ S]methionine-labeled proteins from transformed human amnion cells see also the article by Julio E. Celis, Jette B. Lauridsen, and Bodil Basse). Add 10 1 of overlay solution and fill the tubes with 20 mM NaOH. Fill the upper chamber with 20 mM NaOH and the bottom one with 10 mM H3PO4. Run for 18 hr at 400 V at room temperature. 

Dunnebacke, T. H., 1956, Cytopathic changes associated with poliomyelitis infection in human amnion cells. Virology 2 811. 

Using a genetic approach, Sharpe and Fields (1982) also have examined the effects of the mammalian reoviruses on host cell protein synthesis. Reovirus type 2 was found to inhibit protein synthesis in L cell monolayers more rapidly and efficiently than reovirus type 1 or 3. Type 2 reovirus also inhibits protein synthesis in human amnion cells (Loh and Soergel, 1967). The capacity of type 2 reovirus to... 

Few studies have examined the effects of reovirus type 1 and 2 on host cell macromolecular synthesis. Loh and Soergel (1965) observed that type 2 reovirus inhibits protein and DNA synthesis in human amnion cells but has little effect on RNA synthesis in these cells. Sharpe and Fields (1982) demonstrated that type 2 reovirus produces a decrease in the rate of total RNA synthesis in mouse L cell, whereas, type 3 causes little or no alteration in the rate of RNA... 

Purine metabolism in man is of increasing clinical and experimental interest, but studies of this subject have been hampered by methodological difficulties. This paper describes new methods for the measurement of apparent activities of more than 20 enzymes of purine metabolism in human leukocytes. These methods have also been applied to cultured human lymphoblasts and monolayer cultures of skin fibroblasts and amnionic cells. 

Mixed leukocytes are prepared using dextran sedimentation of erythrocytes, centrifugation of leukocytes from the plasma, and lysis of residual erythrocytes with ammonium chloride. Granulocytes and mononuclear leukocytes are separated from each other and from erythrocytes by density gradient centrifugation using a mixture of Ficoll, Hypaque and dextran. Thirty ml of blood provides sufficient leukocytes for study of adenine, guanine and hypoxanthine metabolism in duplicate. Suspension cultures of human lymphoblasts and leukemic cells, and monolayer cultures of skin fibroblasts and amnionic cells were studied under normal culture conditions approximately 10 cells are required for each incubation. 

Cheng, P. Y. (1961). Size of rapidly labelled ribonucleic acids in human amnion cells. Biochim. Biophys. Acta 53, 235-236. 

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