Biomaterial Database

Unscheduled dna synthesis in confluent and mitotically arrested populations of aging human diploid fibroblasts. 1978

R T Dell'orco, and W L Whittle

Unscheduled DNA synthesis, used as a measure of excision repair following exposure to ultra-violet irradiation, was determined in confluent and arrested human diploid fibroblasts and correlated with in vitro age. Confluent cultures exhibited identical levels of unscheduled DNA synthesis at all in vitro ages. Cells arrested by lowering the serum concentration of the incubation medium exhibited similar levels of unscheduled DNA synthesis as did confluent cells during the first one-third of the cells' characteristic in vitro lifespan. During the last two-thirds of the lifespan, however, arrested populations exhibited a 30 to 50% increase in the amount of detectable DNA repair. This apparent increase in ability to perform unscheduled DNA synthesis was not time or dose dependent and could not be attributed to alterations in precursor pools. It was postulated that the increase may be correlated with changes in DNA structure.

UI	MeSH Term	Description	Entries
D008938	Mitosis	A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.	M Phase, Mitotic,Mitotic M Phase,M Phases, Mitotic,Mitoses,Mitotic M Phases,Phase, Mitotic M,Phases, Mitotic M
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014466	Ultraviolet Rays	That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.	Actinic Rays,Black Light, Ultraviolet,UV Light,UV Radiation,Ultra-Violet Rays,Ultraviolet Light,Ultraviolet Radiation,Actinic Ray,Light, UV,Light, Ultraviolet,Radiation, UV,Radiation, Ultraviolet,Ray, Actinic,Ray, Ultra-Violet,Ray, Ultraviolet,Ultra Violet Rays,Ultra-Violet Ray,Ultraviolet Black Light,Ultraviolet Black Lights,Ultraviolet Radiations,Ultraviolet Ray
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In