2D modelling of nucleus location in lymphoid cells.
Cytologists have seldom made a quantitative study of the location of the nucleus within the cell. We have mathematically defined three parameters in two dimensions: the number of distinct cell/nucleus boundary contacts (Ncon), the length of such contacts (Lcon), and the degree of nucleus location eccentricity (Ecc), expressed as a function of the greatest distance between cell and nucleus boundaries, and of the nucleus/cytoplasm ratio (N/C). Based on the analysis of 68 circular or elongated cell and nucleus models, we identify 21 topographies, for a range of N/C values between 20% and 70% and for a range of cell surface area values between 2900 and 6700 pixels on a hexagonal raster (256 x 256). Beyond 70%, a maximum of two topographies may be distinguished; below 20%--a figure nearer a nucleolus-nucleus ratio--the relevance and reliability of the approach are subject to some doubt. We conclude that the problem of describing the location of one structure within another remains dependent on N/C. The method has been applied to 59 lymphoid cells on smear photographs recognized internationally by hematologists as characteristic of lymphoid diseases. The results show the robustness of the combination of four criteria in relation to the overall elongation of nucleus or cell profiles, and to significant contour irregularities. The method has demonstrated its ability to describe and quantify the eccentric position of the nucleus within plasmocytic lymphocytes, and provide a further degree of discrimination.
Lesty
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Laboratoire de Morphométrie du départment d'hématologie, Faculté de médecine, Pitié-Salpêtrière, Paris, France.
D001853:Bone Marrow / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure*; D048429:Cell Size; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008214:Lymphocytes / Q000648:ultrastructure; D008221:Lymphoid Tissue / Q000473:pathology / Q000648:ultrastructure*; D008954:Models, Biological; D010950:Plasma Cells / Q000648:ultrastructure; D015203:Reproducibility of Results