Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1984-4-24
pubmed:abstractText
Lymphocytes from humans over the age of 65 incorporate approximately 50% less tritiated thymidine than do lymphocytes from young donors when cultured with phytohemagglutinin. Because lymphocytes from elderly humans are more sensitive to cell cycle arrest induced by tritiated thymidine, it was impossible to determine to what extent impaired thymidine incorporation reflected a defect in proliferation or the increased sensitivity to the radioactive isotope. Flow cytometry was used to measure the proliferative response of T cells from young and old donors in culture with PHA. It was found that 25 percent fewer lymphocytes from old as compared to young humans enter the G1 or complete the S phase of the cell cycle. However, the rate of progression through the cell cycle by activated cells from young and old humans is comparable. Thus, flow cytometry suggested that the difference in thymidine incorporation by lymphocytes from old and young donors is attributable equally to a proliferative defect and to cell cycle arrest induced by tritiated thymidine. This conclusion was supported by the fact that the relative impairment of thymidine incorporation by lymphocytes from old donors was only one-half as great when a 20-min instead of a 24-hr pulse of tritiated thymidine was used.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1788-92
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Immunological studies of aging. IX. Impaired proliferation of T lymphocytes detected in elderly humans by flow cytometry.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.