The method of moments as applied to the study of granulocytes' shape and movement

The paper presents an approach to the quantitative analysis of the shape and motion of migrating granulocytes based on the method of moments. A computer image analysis system and a specially designed program were used. The following features of cells and cell locomotion have been calculated: the cell centre of gravity and its coordinates, the cell displacement, the main cell axis, the coefficient describing cell elongation and the parameters of cell orientation. In order to evaluate the above approach under various conditions, comparative experiments were performed using the media of different viscosity and various positions of the plane on which the granulocytes were migrating. The cell shape and locomotion parameters estimated in various series of experiments indicate that the method may be generally useful and is able to detect not only major features of cell shape and movement, but also their relatively slight variations. The experiments performed in basic (typical) conditions revealed that the main axis of the majority of cells (about 60%) does not deviate from the global direction of migration by an angle greater than 30 degrees; about 10% of cells move with the main axis perpendicular to this direction. The broader frontal part of granulocytes is directed forward with regard to the global movement direction in 58% of cells, whereas 28% of the cells move with the tail pointing forward. The results of joint analysis of the cell shape and motion have confirmed statistically some well known features of migrating granulocytes.(ABSTRACT TRUNCATED AT 250 WORDS)