Effect of lead on fibroblasts taken from an 84-year-old donor.

Human, diploid fibroblasts from an 84-year-old donor (AlPos) were used to study the effect of 20, 40 and 80 micrograms/100 ml concentrations of lead on in vitro senescence. The results showed that there was a significant decrease in the number of total population doublings due to the treatment with lead. However, there was no significant difference between the effects of the three concentrations of lead.

Amphibian cell culture: established fibroblastic line from embryos of the discoglossid frog, Bombina orientalis.

A new amphibian cell line, Bor II, is described. It was initiated from Stage 20 embryos of the discoglossid frog, Bombina orientalis. In early passages the cell line had an epithelioid morphology.

The effect of clinical and subclinical concentrations of lead on the in vitro aging of human fibroblasts.

The effect of 20, 40 and 80 micrograms per 100 ml concentrations of lead on the in vitro senescence of fetal human diploid fibroblasts IMR-90 was determined. The areas and dry mass of the cell, nucleus and nucleolus were measured at early, middle and late passages. There was a decrease in total population doublings as the concentration of lead in the medium was increased.

Determination of the nuclear RNA content of cells from donors of three different ages during in vitro senescence.

Diploid fibroblasts from male donors aged 8, 40 and 84 years were grown in vitro and their nuclear RNA content was determined at early and late doublings by absorption cytophotometry after staining with Azure B for 2 hours at 40 degree C and pH 4. It was found that the average nuclear RNA content of the early doublings was lower than that of the last doubling in all three strains. This difference became smaller as donor age increased.

Cytological changes senescing WI-38 cells: a statistical analysis.

Changes in the cell, nuclear, nucleolar dry masses and areas were monitored simultaneously during in vitro senescence of WI-38 human fetal lung fibroblast cells, and the results were analyzed statistically. There was a two-step increase in all six parameters studied, following an initial decrease. The patterns of increase were strikingly similar for all six measures, i.