The cell sectioning model. Nuclear/cytoplasmic ratio studied by computer simulation

Stereologic analysis can be supported using methods of modeling and simulation. To illustrate the use of a mathematical cell sectioning model (CSM) in predicting two-dimensional (2-D) measurement characteristics of sectioned cells by means of computer-assisted simulation, the present study was performed.

Computer software based on the CSM was developed to simulate 2-D nuclear/cytoplasmic (N/C) ratio distributions and to test the sensitivity of the parameter to several factors. Simulations were performed with the following feature set for cells of simulated populations: (1) size, shape (approximated by an ellipsoid of rotation) and orientation of the cell, and (2) size, shape and intracellular position of the nucleus.

The computer tests showed that the value of the 2-D N/C ratio depends upon many factors; the real three-dimensional N/C ratio is only one. Statistical characteristics of a 2-D N/C ratio sample were found to be sensitive to changes in (1) the nuclear position inside the cell, (2) cell shape, and (3) orientation of the asymmetric cell with respect to a cutting plane.

CSM tests demonstrated the model validity of and potentials for using it as an algorithm for morphometry software. Taking into account the sensitivity of the 2-D N/C ratio parameter to various factors, great care must be used in interpreting its observations.