Biomaterial Database

Biological time and the effects of hydroxyurea on DNA synthetic activity of bone marrow and tumor cells in mice bearing the Ehrlich ascites carcinoma. 1987

E R Burns

The objective of this experiment was to attempt to induce, with hydroxyurea (HU), significant quantitative differences in the level of DNA-synthetic activity (DNA-SA) between a neoplastic cell population (the Ehrlich ascites carcinoma or EAC) and bone marrow in the same animal. Mice bearing a 5-day-old EAC were standardized to and kept on an LD 12:12 cycle (light 0600-1800 hr). They were treated with 500 mg/kg HU at 0500 hr (23 hr after lights on, or HALO) or at 1700 hr (11 HALO). DNA-SA was determined by liquid scintillation counting of 3H-thymidine incorporation into chemically isolated DNA. DNA-SA in bone marrow and EAC cells was monitored over the next 60 hr with subgroups of ten mice each killed every 3 hr beginning 3 hr after treatment with HU. The circadian system of the host influenced the response of the bone marrow to HU; i.e., the response to HU administered at 0500 hr was different both qualitatively and quantitatively from that for HU given at 1700 hr. Comparisons of DNA-SA in bone marrow and EAC from the same animal revealed time points after treatment with HU when DNA-SA in the EAC was high, but DNA-SA in bone marrow was low. These differences in the level of DNA-SA between a tumor cell population and bone marrow should be of therapeutic value; i.e., executor doses of anti-DNA-SA drugs such as cytosine arabinoside could be given at that point in time after treatment with HU when DNA-SA in the tumor was high, but DNA-SA in the bone marrow was low.

UI	MeSH Term	Description	Entries
D001853	Bone Marrow	The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.	Marrow,Red Marrow,Yellow Marrow,Marrow, Bone,Marrow, Red,Marrow, Yellow
D002286	Carcinoma, Ehrlich Tumor	A transplantable, poorly differentiated malignant tumor which appeared originally as a spontaneous breast carcinoma in a mouse. It grows in both solid and ascitic forms.	Ehrlich Ascites Tumor,Ascites Tumor, Ehrlich,Ehrlich Tumor Carcinoma,Tumor, Ehrlich Ascites
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
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
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D004273	DNA, Neoplasm	DNA present in neoplastic tissue.	Neoplasm DNA
D004334	Drug Administration Schedule	Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.	Administration Schedule, Drug,Administration Schedules, Drug,Drug Administration Schedules,Schedule, Drug Administration,Schedules, Drug Administration
D006918	Hydroxyurea	An antineoplastic agent that inhibits DNA synthesis through the inhibition of ribonucleoside diphosphate reductase.	Hydroxycarbamid,Hydrea,Oncocarbide
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia