[Labeled mitosis curve in the presence of different states of cell proliferation kinetics. IV. Additional remarks on the method of a posteriori modeling].

Using the conditional probability density function of phase duration--h (a, t), defined for a cell just completing a given phase of the mitotic cycle at the moment t it is possible to construct a mathematical description of the fraction labeled mitoses curve. The function h (a, t) defined for any separate phase can be described by means of a certain mathematical expression which is applicable even in the presence of transient processes in cell kinetics and serves as an appropriate generalization of the same result from the theory of exponentially growing cell populations (the model of age-dependent branching process). When the sum of r successive phases with stochastically dependent durations is under consideration and the age of a cell is measured from the start of phase r, it is necessary to find out the expression for the function hr (ar, t). The derivation of such an expression is given.