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Author

M. V. O'Shaughnessy

Bio: M. V. O'Shaughnessy is an academic researcher. The author has contributed to research in topics: Interferon & Thymidine. The author has an hindex of 1, co-authored 1 publications receiving 49 citations.

Papers
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Journal ArticleDOI
TL;DR: Using monodispersed cell suspensions, interferon preparations were shown to have both a lethal and a growth-depression effect in the same concentration range as that required for antiviral activity.
Abstract: Using monodispersed cell suspensions, interferon preparations were shown to have both a lethal and a growth-depression effect in the same concentration range as that required for antiviral activity. In addition, synchronized cells treated with interferon respond by delaying their normal uptake of thymidine during S phase until after a period during which new protein is synthesized. Puromycin added during this period prevents both the synthesis of this protein and the subsequent synthesis of DNA.

49 citations


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Book
01 Jan 2006
TL;DR: Animal Models and Therapy, Directed Differentiation and Characterization of Genetically Modified Embryonic Stem Cells for Therapy, and Use of Differentiating Embryonics Stem cells in the Parkinsonian Mouse Model are reviewed.
Abstract: Isolation and Maintenance.- Isolation and Differentiation of Medaka Embryonic Stem Cells.- Maintenance of Chicken Embryonic Stem Cells In Vitro.- Derivation and Culture of Mouse Trophoblast Stem Cells In Vitro.- Derivation, Maintenance, and Characterization of Rat Embryonic Stem Cells In Vitro.- Derivation, Maintenance, and Induction of the Differentiation In Vitro of Equine Embryonic Stem Cells.- Generation and Characterization of Monkey Embryonic Stem Cells.- Derivation and Propagation of Embryonic Stem Cells in Serum- and Feeder-Free Culture.- Signaling in Embryonic Stem Cell Differentiation.- Internal Standards in Differentiating Embryonic Stem Cells In Vitro.- Matrix Assembly, Cell Polarization, and Cell Survival.- Phosphoinositides, Inositol Phosphates, and Phospholipase C in Embryonic Stem Cells.- Cripto Signaling in Differentiating Embryonic Stem Cells.- The Use of Embryonic Stem Cells to Study Hedgehog Signaling.- Transfection and Promoter Analysis in Embryonic Stem Cells.- SAGE Analysis to Identify Embryonic Stem Cell-Predominant Transcripts.- Utilization of Digital Differential Display to Identify Novel Targets of Oct3/4.- Gene Silencing Using RNA Interference in Embryonic Stem Cells.- Genetic Manipulation of Embryonic Stem Cells.- Efficient Transfer of HSV-1 Amplicon Vectors Into Embryonic Stem Cells and Their Derivatives.- Lentiviral Vector-Mediated Gene Transfer in Embryonic Stem Cells.- Use of the Cytomegalovirus Promoter for Transient and Stable Transgene Expression in Mouse Embryonic Stem Cells.- Use of Simian Immunodeficiency Virus Vectors for Simian Embryonic Stem Cells.- Generation of Green Fluorescent Protein-Expressing Monkey Embryonic Stem Cells.- DNA Damage Response and Mutagenesis in Mouse Embryonic Stem Cells.- Ultraviolet-Induced Apoptosis in Embryonic Stem Cells In Vitro.- Use of Embryonic Stem Cells in Pharmacological and Toxicological Screens.- Use of Differentiating Embryonic Stem Cells in Pharmacological Studies.- Embryonic Stem Cells as a Source of Differentiated Neural Cells for Pharmacological Screens.- Use of Murine Embryonic Stem Cells in Embryotoxicity Assays.- Use of Chemical Mutagenesis in Mouse Embryonic Stem Cells.- Epigenetic Analysis of Embryonic Stem Cells.- Nuclear Reprogramming of Somatic Nucleus Hybridized With Embryonic Stem Cells by Electrofusion.- Methylation in Embryonic Stem Cells In Vitro.- Tumor-Like Properties.- Identification of Genes Involved in Tumor-Like Properties of Embryonic Stem Cells.- In Vivo Tumor Formation From Primate Embryonic Stem Cells.- Animal Models and Therapy.- Directed Differentiation and Characterization of Genetically Modified Embryonic Stem Cells for Therapy.- Use of Differentiating Embryonic Stem Cells in the Parkinsonian Mouse Model.

3,665 citations

Journal ArticleDOI
21 Jul 1977-Nature
TL;DR: A suppressive effect of interferon on the transition from the quiescent to the growing state in BALB/c 3T3 cells is described and the data indicate that Interferon suppresses the initiation of DNA synthesis.
Abstract: PAUCKER, Cantell and Henle reported that crude mouse interferon preparations depressed multiplication of suspended L cells1. Since then evidence has accumulated indicating that interferon molecules which inhibit multiplication of virus also inhibit the growth of cells in culture2–9. Interferon was shown to suppress incorporation of 3H-thymidine into cellular DNA in various systems—for example, release from a double thymidine block in synchronised L929 cells10; activation of mouse spleen lymphocytes by phytohaemagglutinin (PHA) or allogeneic lymphocytes11; and in steady-state growth of cultured mouse leukaemia L 1210 cells12 in a chemostat. However, there has been no direct evidence to distinguish between the effect of interferon on the rate of initiation of DNA synthesis (entry into the S phase) and that on the rate of DNA synthesis in the S phase, and it is uncertain which step of the cell cycle is interfered by interferon. It is well known that most cells in cultures of confluent or serum starved mouse 3T3 stay in the early G1 or GO stage of the cell cycle, and an addition of serum to these quiescent cells stimulates their growth, leading to DNA synthesis and cell division13,14. We describe here a suppressive effect of interferon on the transition from the quiescent to the growing state in BALB/c 3T3 cells. The data indicate that interferon suppresses the initiation of DNA synthesis.

88 citations

Journal ArticleDOI
TL;DR: Interferon was first described by Isaacs and Lindenmann (1957) and characterized as an antiviral substance produced by the cells of many vertebrates in response to virus infection as discussed by the authors.
Abstract: Interferon was first described in 1957 by Isaacs and Lindenmann (1957) and characterized as “an antiviral substance produced by the cells of many vertebrates in response to virus infection. It appears to be of protein or polypeptide nature, it is antigenically distinct from virus, and it acts by conferring on cells resistance to the multiplication of a number of different viruses” (Isaacs, 1963). Although this description still has some validity today, there is considerable evidence indicating that interferon is not a selective antiviral substance, but that it can also affect both cell division and cell function.

83 citations

Journal ArticleDOI
TL;DR: It is concluded that, at a sufficient dose, the human glioma cell line U‐251 MG was unable to accomplish cell division as they prematurely stopped synthesizing DNA.
Abstract: The human glioma cell line U-251 MG, with a well-characterized defect in growth control, was sensitive to the antiproliferative effects of human (fibroblast) interferon (IFN). IFN inhibited exponentially growing cells by increasing the number of cells in the S stage of the cell cycle. At the same time the number of cells in Go/G1 diminished. The rate of thymidine incorporation was decreased during the first cell cycle, with no prolongation of S. However, in synchronized cultures, the wave of cells with a S-phase content did not decrease over a time period several hours longer than the length of S measured by pulse labelling. Thus we conclude that, at a sufficient dose, the cells were unable to accomplish cell division as they prematurely stopped synthesizing DNA.

78 citations