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Volume 8 (1989 - 1990･･･
- Issue 2 Pages 1-
- Issue 1 Pages 23-
Volume 8, Issue 2
Displaying 1-7 of 7 articles from this issue
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Masayoshi Namba, Shigeharu Nakatsuka, Teruyuki Kawabata1990 Volume 8 Issue 2 Pages 1-5
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSNitrilotriacetate (NTA), N(CH2COOH)3, asynthetic aminopolycarboxylic acid chelator, binds iron and forms Fe-NTA complex. This complex enhanced colony formation of various types of cultured cells. In addition, Fe-NTA stimulated proliferation of cells in mass cultures. NTA alone had no enhancing effects on cell growth. These results indicate that Fe-NTA may be employed as a substitute for Fe-transferrin as an iron donor to cells. The use of Fe-NTA would thus make it possible to reduce the serum concentrations employed in commonly used culture media.View full abstractDownload PDF (824K) -
Toshimitsu Suzuki, Masayuki Hirota, Makoto Iwabuchi, Nobuo Nomura, Fum ...1990 Volume 8 Issue 2 Pages 6-15
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSA new human neuroblastoma cell line designated NB-39-nu has been established from a human neuroblastoma serialy heterotransplanted in athymic nude mice. The cell line was potentially adrenergic, since intraperitoneal inoculation of NB-39-nu into athymic mice produced a neuroblastoma of rosette-fibrillary type with tyrosine hydroxylaseimmunoreactivity.
Population doubling time was 41 hrs in the MEM medium and 22 hrs in the RPMI-1640medium. Modal chromosome number was 83. Karyotypic analysis revealed the structural aberrations of #1 and #2 chromosomes and homogeneously staining regions were inserted within the long arm of chromosome # 10. Ultrastructurally the cell line was mainly immature neuroblastic cells but a few of moderately differentiated neuroblastic cells were also included. Dibutyryl cyclic AMP, retinoic acid and cholera toxin but not nerve growth factor induced outgrowth of neurites without any detectable biochemical differentiation. Oncogene analysis indicated amplification of N-myc DNA and over-expression of its mRNA. The level of N-myc mRNA, however, did not change after the treatment of the cell line with dibutyryl cyclic AMP or retinoic acid.View full abstractDownload PDF (4620K) -
Robert B. Dickson1990 Volume 8 Issue 2 Pages 16-30
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSDownload PDF (3228K) -
Toshinori Kanamorii, Hideaki Morishita, Hiromi Hagino, Kouichi Noda, A ...1990 Volume 8 Issue 2 Pages 31-39
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSHuman tissue-type plasminogen activator (t-PA) gene was expressed in human cell lines, into which the gene was transfected.
HeLa cells were transfected with a plasmid carrying neo, dhfr and t-PA gene which was controlled by β-actin promotor or SV40 early promoter. The clones grown in media with G-418were analyzed for evaluating the activities of both promoters. On regard to the expression of t-PA gene in HeLa cells, β-actin promoter exerted more efficacious than SV40 early promoter.
Difference was observed in average t-PA levels in the cultured media of G-418-resistant clones from three cell lines ( HeLa, WI-38 VA13 and KMS-5) transfected with t-PA-expression plasmid with β-actin promoter. Southern blotanalysis revealed that the copy number of t-PA gene in each clone was likely responsible for the amount of t-PA produced.
G-418-resistant HeLa clone was cultured in media with increasing concentration of methotrexate (MTX). MTX-treatment succeeded to evolve a high t-PA producing clone with high copy number of t-PA gene, and t-PA producing level of a resulting clone was kept constantly for 5 months.View full abstractDownload PDF (2622K) -
Hideki YANAGI1990 Volume 8 Issue 2 Pages 40-42
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSWe studied expression of cDNAs for human erythropoietin (EPO) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in human lymphoblastoid Namalwa cells. The following results indicate that Namalwa cells have desirable characteristics as a host cell line to produce recombinant human glycoproteins: i)High-level expression such as 1-2μg/106 cells/day for EPO and 10-20μg/106 cells/day for GM-CSF was achieved. ii) Exogenous DNA was amplified in Namalwa cells. iii) Almost all N-linked oligosaccharides of Namalwa-derived EPO were shared by human urinary EPO. iv) Highly expressive transformants were readily adapted to grow in serum-free medium.View full abstractDownload PDF (544K) -
Takafumi Ochi1990 Volume 8 Issue 2 Pages 43-47
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSEffects of glutathione depletion by L-buthionine-SR-sulfoximine (BSO), a selective inhibitor of γglutamylcysteine synthetase, and metallothionein induction by zinc on the cytotoxicity of cadmium (Cd) were investigated in cultured Chinese hamster V79 cells. Cd toxicity increased with increased duration of BSO treatment which was paralleled with decrease in the level of cell glutathione. Metallothionein (MT) synthesis by zinc was induced with a lag time of 2 h and reached a maximum 10 to 12 h after zinc addition. Presence of BSO did not very much influence MT synthesis by zinc. Preinduction of MT suppressed Cd toxicity almost completely, even on the induction in the presence of BSO. From these observations, it is proposed that glutathione and MT have cooperative protective roles against Cd toxicity, as an initial defense for the former and a second-stage defense for the latter.View full abstractDownload PDF (778K) -
Masayasu Yamada, Makoto Kawaguchi, Chiharu Moritoh, Hiroyoshi Wada, To ...1990 Volume 8 Issue 2 Pages 48-60
Published: March 31, 1990
Released on J-STAGE: November 13, 2012
JOURNAL FREE ACCESSDownload PDF (7223K)
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