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Biomedical subjects

J B Baker

Publications and source records attributed to J B Baker.

61 records · Page 4Linked to original sources
PubMed1972

Turnover of molecules which maintain the normal surfaces of contact-inhibited cells.

In confluent cultures normal chick embryo fibroblasts become highty agglutinable by concanavalin A within 6 hours after their synthesis of protein is inhibited by cycloheximide, pactamycin, or emetine. When growing cells are similarly treated, they fail to become more agglutinable. Apparently, molecules which maintain the normal structure of the cell surface must be replaced continually when cell growth is contact inhibited.

Agglutination↗
PubMed1971

Serum-stimulated release of cell contacts and the initiation of growth in contact-inhibited chick fibroblasts.

Increased serum concentration in the medium of a confluent culture increases the overlapping of cells and the average rate of cell movement. The relationship between these two serum activities and serum release of growth inhibition was studied. The increase in overlaps does not appear to be directly related to release of growth since it occurs well after growth has been initiated. The increased rate of cell movement occurred immediately after the addition of serum and was quantitatively proportional to the stimulation of DNA synthesis over a range of serum concentrations, implying that both movement and growth are released by a common serum activity. Direct microscopic observation and time-lapse films reveal a reduction in cell contacts concurrent with the increase in cell movement. Experiments showed that cell movement at low cell densities, where cell contacts are minimal, was rapid in low serum concentration and was not stimulated by increasing the serum concentration. This suggests that the serum effect on cell movement involves cell contacts and is due to release of cell contacts in the confluent monolayer. The primary action of serum may be the disruption of adhesive cell contacts.

Animals↗