title: Cell population size dependency of therapeutic effect of divided dosage of 1-beta-D-arabinofuranosylcytosine.
abstract: A total dose of 960 mg/kg body weight of 1-beta-D-arabinofuranosylcytosine (cytosine arabinoside) was given intraperitoneally to rats bearing Yoshida sarcoma, in a single or divided doses. Single-dose therapy gave an increased life span of about 1 day irrespective of cell population size in accord with the concept of constant percentage cell kill. Tumor cell reduction was estimated to be about 70%. Divded-dose therapy, however, brought about increased life span which was reciprocally proportional to the logarithm of population size. Estimated cell reduction was 87% when population size was 10(8) cells and 99.95% at 10(4) cells.
mesh_terms: D000818:Animals; D002452:Cell Count; D002470:Cell Survival / Q000187:drug effects; D003561:Cytarabine / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D051381:Rats; D012517:Sarcoma, Yoshida / Q000188:drug therapy* / Q000473:pathology
chemical_list: D003561:Cytarabine