scholarly journals Production of High-Titered Interferon in Cultures of Human Diploid Cells

1972 ◽  
Vol 2 (6) ◽  
pp. 476-484 ◽  
Author(s):  
E. A. Havell ◽  
J. Vilcek
Keyword(s):  
Human Diploid Cells ◽  
Diploid Cells

Results of chromosome analysis of rabies virus infected human diploid cells (WI-38)

1977 ◽  
Vol 54 (3) ◽  
pp. 255-257 ◽  
Author(s):  
M. Majer ◽  
Annelies Herrmann ◽  
R. Mauler
Keyword(s):  
Rabies Virus ◽  
Chromosome Analysis ◽  
Human Diploid Cells ◽  
Diploid Cells

Growth of human diploid cells (strain MRC-5) in defined medium; replacement of serum by a fraction of serum ultrafiltrate

1979 ◽  
Vol 35 (1) ◽  
pp. 381-392
Author(s):  
K. Lambert ◽  
S.J. Pirt
Keyword(s):  
Amino Acids ◽  
Active Material ◽  
Maximum Yield ◽  
Calf Serum ◽  
Defined Medium ◽  
Cell Yield ◽  
Maximum Cell ◽  
Macromolecular Component ◽  
Human Diploid Cells ◽  
Diploid Cells

A calf serum ultrafiltrate fraction permitted growth for at least 3.5 generations, including one subculture, of MRC-5 cells in defined medium in the absence of whole serum. The active material has a molecular weight of 10 000 Daltons or less. This suggests that there may be no requirement for a large macromolecular component of serum. The ultrafiltrate was assayed by maximum cell yield from a serum-limited inoculum in a defined medium containing non-limiting amounts of vitamins, amino acids, glucose, a 68-component supplement, iron and methylcellulose. The levels of vitamins, amino acids and glucose were based on quantitative measurements of uptake and the levels of the other components by minimum amount required for maximum yield in defined medium without ultrafiltrate or serum. With excess ultrafiltrate maximum cell yield was limited by the defined part of the medium, probably the supplement. The cell doubling time in defined medium with ultrafiltrate fractions was 70 h compared with 27 h in the medium with serum. Excess ultrafiltrate did not inhibit growth. The lowered growth rate is attributed to a nutritional deficiency in the supplement.

Efficient transfer of cloned DNA into human diploid cells: protoplast fusion in suspension

1984 ◽  
Vol 4 (11) ◽  
pp. 2549-2552
Author(s):  
P Litzkas ◽  
K K Jha ◽  
H L Ozer
Keyword(s):  
Simian Virus 40 ◽  
Cell Types ◽  
Simian Virus ◽  
Selective Medium ◽  
T Antigen ◽  
Human Diploid Fibroblasts ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Human Diploid Cells ◽  
Diploid Cells

A method for fusion of protoplasts bearing amplified plasmids and human diploid fibroblasts or other cell types in suspension is described. Transient expression of plasmid-encoded proteins occurs in up to 50% of the human cells, as demonstrated for simian virus 40 T antigen by immunofluorescence and the Escherichia coli xanthine-guanine phosphoribosyl transferase by autoradiography. In contrast, frequencies of stable transformants were similar to those obtained by the CaPO4 coprecipitation technique. However, experiments with both methods involving the recombinant pRSVneo (in which the Rous sarcoma virus long terminal repeat regulates expression of the antibiotic-inactivating aminoglycoside phosphotransferase) revealed a much higher frequency of colonies in G418 selective medium with constructions in which the early region of simian virus 40 DNA was present as well. We propose a role for the simian virus 40 T antigen in enhancing stable transformation in this system.

scholarly journals ASYNCHRONY OF DNA SYNTHESIS IN CHROMOSOMES OF HUMAN DIPLOID CELLS

1963 ◽  
Vol 16 (1) ◽  
pp. 202-209 ◽  
Author(s):  
P. S. Moorhead ◽  
Vittorio Defendi
Keyword(s):  
Dna Synthesis ◽  
Human Diploid Cells ◽  
Diploid Cells

The analysis of malignancy by cell fusion. VIII. Evidence for the intervention of an extra-chromosomal element

1977 ◽  
Vol 24 (1) ◽  
pp. 255-263
Author(s):  
J. Jonasson ◽  
H. Harris
Keyword(s):  
Human Chromosome ◽  
Gamma Radiation ◽  
Cell Fusion ◽  
Human Fibroblasts ◽  
Melanoma Cells ◽  
Human Chromosomes ◽  
Mouse Melanoma ◽  
Human Diploid Cells ◽  
Diploid Cells ◽  
Hybrid Clones

Diploid human fibroblasts and lymphocytes were fused with the cells of a malignant mouse melanoma and a range of hybrid clones selected for study. The ability of these clones to produce progressive tumours was assayed in nude mice. Although human chromosomes were preferentially eliminated in all the hybrid clones, the human diploid cells were as effective as mouse diploid cells in suppressing the malignancy of the mouse melanoma cells. The suppression produced by fibroblasts was again more profound than that produced by lymphocytes. Malignancy was also found to be suppressed in a hybrid clone in which a single X was the only human chromosome present; and this clone continued to give a very low take incidence even after the human X had been eliminated by back selection. Hybrids were made between the melanoma cells and diploid human fibroblasts that had been given 100 J kg-1 of gamma radiation before cell fusion. These hybrids contained no recognizable human chromosomes, but their ability to produce progressive tumours was greatly reduced compared to that of the melanoma parent cells. The take incidences given by the crosses between the melanoma cells and the irradiated human fibroblasts were, however, substantially higher than those given by the crosses between the melanoma cells and unirradiated fibroblasts. These findings suggest that the suppression of malignancy involves the activity of some extra-chromosomal element and that this element is radio-sensitive.

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