title: Growth kinetics of plasma cell myeloma.
abstract: The plasma cell labeling index(ex) (LI) of 128 patients with multiple myeloma at various stages of disease was compared as a function of tumor mass load and length of treatment. No significant differences in LI were noted for patients with various degrees of tumor reduction. Patients observed during the first 3 months of treatment had significantly higher LI than did untreated patients and those studied after longer intervals. In vivo cell-cycle analysis of myeloma cells by the halving time of the grain-count method failed to establish the length of the cell cycle but defined the length of S+G2 phases as being longer than 60 hours. Similar studies conducted in vitro defined a shorter combined length of S+G2 phase. In 2 patients in whom continuous infusion with [3H] thymidine was performed, the generation time was established as 8 days. Both patients had similar initial LI (5.7 and 6.6) but different growth fractions (19 and 47%). The measured tumor mass doubling time was much longer than the calculated one, suggesting the presence of considerable intrinsic cell loss (83 and 47%). These observations were summarized by a hypothetical two-compartment model for the growth kinetics of multiple myeloma.
mesh_terms: D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D001854:Bone Marrow Cells; D002455:Cell Division; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007263:Infusions, Parenteral; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D009101:Multiple Myeloma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D012008:Recurrence; D013936:Thymidine / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D013936:Thymidine