Feline sarcoma virus induced in vitro progression from premalignant to neoplastic transformation of human diploid cells

In Vitro ◽  
1980 ◽  
Vol 16 (9) ◽  
pp. 813-822 ◽  
Author(s):  
George E. Milo ◽  
Richard G. Olsen ◽  
Steven E. Weisbrode ◽  
John A. McCloskey
Keyword(s):  
Neoplastic Transformation ◽  
Sarcoma Virus ◽  
Human Diploid Cells ◽  
Diploid Cells

X-ray-induced in vitro Neoplastic transformation of human diploid cells

Nature ◽  
1980 ◽  
Vol 283 (5749) ◽  
pp. 776-778 ◽  
Author(s):  
Carmia Borek
Keyword(s):  
Neoplastic Transformation ◽  
X Ray ◽  
Human Diploid Cells ◽  
Diploid Cells

Neoplastic transformation of human diploid cells in vitro after chemical carcinogen treatment

Nature ◽  
1978 ◽  
Vol 275 (5676) ◽  
pp. 130-132 ◽  
Author(s):  
GEORGE E. MILO ◽  
JOSEPH A. DIPAOLO
Keyword(s):  
Neoplastic Transformation ◽  
Chemical Carcinogen ◽  
Human Diploid Cells ◽  
Diploid Cells

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 The effect of oxygen and vitamin E on the lifespan of human diploid cells in vitro.

1977 ◽  
Vol 74 (1) ◽  
pp. 58-67 ◽  
Author(s):  
A K Balin ◽  
D B Goodman ◽  
H Rasmussen ◽  
V J Cristofalo
Keyword(s):  
Oxygen Toxicity ◽  
Alpha Tocopherol ◽  
Ambient Oxygen ◽  
Oxygen Tensions ◽  
Effect Of Oxygen ◽  
Population Doublings ◽  
Human Diploid Cells ◽  
Diploid Cells ◽  
Phase Out

Human diploid cells (WI-38) were serially subcultivated at partial pressures of oxygen (Po2) ranging from 5.6 mm Hg to 608 mm Hg. At a Po2 of 5.6 mm Hg, the number of doublings to phase out was less than that of control cells at a Po2 of 137 mm Hg. Cultures grown at Po2's of 24, 49, or 137 mm Hg grew at the same rate and phased out after a similar number of population doublings. Population lifespan was markedly shortened by chronic exposure to elevated Po2's, a phenomenon that was, in part, reversible. d-1-alpha-Tocopherol (10 microgram/ml or 100 microgram/ml) homogenized into the medium at each weekly subcultivation did not extend the lifespan of cells at reduced, ambient, or elevated oxygen tensions. These results indicate that neither oxygen toxicity nor free radical reactions play a significant role in limiting the lifespan of WI-38 cells grown in vitro under ambient oxygen tensions (Po2 137 mm Hg).

Doubling potential and calendar time of human diploid cells in vitro

1979 ◽  
Vol 14 (6) ◽  
pp. 329-334 ◽  
Author(s):  
K. Kaji ◽  
M. Matsuo
Keyword(s):  
Calendar Time ◽  
Human Diploid Cells ◽  
Diploid Cells

Clonal lifespan of Paramecium tetraurelia: effect of selection on its extension and use of fissions for its determination

1987 ◽  
Vol 88 (1) ◽  
pp. 129-138
Author(s):  
Y. Takagi ◽  
T. Nobuoka ◽  
M. Doi
Keyword(s):  
Marked Effect ◽  
Marker Genes ◽  
Paramecium Tetraurelia ◽  
Random Events ◽  
The Mean ◽  
Human Diploid Cells ◽  
Diploid Cells ◽  
Poor Nutrition ◽  
Selection Of

Paramecia cells, like human diploid cells cultured in vitro, provide a useful model system for understanding the mechanism that limits division potential. The reported maxima of the clonal lifespan of Paramecium tetraurelia fall into two ranges: from 220 to 258 fissions and from 310 to 325 fissions. We found that neither the selection of vigorous lines nor the cryptic occurrence of autogamy offers a plausible explanation for the much longer lifespans in the latter range. We found the sporadic occurrence of very long clonal lifespans, such as 330 fissions, without selection and autogamy. Selection, which was evaluated by using different methods to maintain lines, had little effect on the extension of the maximal clonal lifespan, whereas it did have a marked effect on the extension of the mean clonal lifespan. Autogamy, which was checked with two closely linked marker genes, was frequent, but only during the period when lines were terminating. Statistical analysis on the mean clonal lifespans of two groups of subclones cultured at 25 and 20 degrees C or with rich and poor nutrition showed that the clonal lifespan that was fission-related under favourable conditions tended to dissociate from fissions under less favourable conditions. We discuss mechanisms that determine the clonal lifespan, programmed events contributing to the maximum clonal lifespan and random events contributing to the mean clonal lifespan.

Cell-associated pentosidine as a marker of aging in human diploid cells in vitro and in vivo

1998 ◽  
Vol 105 (3) ◽  
pp. 221-240 ◽  
Author(s):  
David R Sell ◽  
Michael Primc ◽  
Irwin A Schafer ◽  
Maureen Kovach ◽  
Miriam A Weiss ◽  
...  
Keyword(s):  
Human Diploid Cells ◽  
Diploid Cells
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