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Biomedical subjects

V I Samoilov

Publications and source records attributed to V I Samoilov.

9 recordsLinked to original sources
PubMed1994

Morphogenetic response of cultured normal and transformed fibroblasts, and epitheliocytes, to a cylindrical substratum surface. Possible role for the actin filament bundle pattern.

Morphometric characteristics such as cell area, dispersion, elongation and orientation were studied in normal and transformed fibroblasts, and in epitheliocytes cultured on flat or cylindrical substrata. Cylindrical surfaces with a high degree of curvature (12-13 or 25 microns radii) were shown to affect cell size, shape and alignment. The reaction of the cells to the curvature of cylindrical substrata was different in various cell types studied and depended on the pattern of actin microfilament bundles. The cells containing pronounced straight actin bundles (mouse embryo fibroblasts at the polarization stage of spreading, single spread cells of the 'normal' epithelial FBT line or the fully transformed epithelial IAR 6-1 line) were relatively resistant to bending around a cylindrical substratum, and became elongated and oriented along the cylinder. Cells with circular actin bundles as the predominant pattern (mouse embryo fibroblasts at the radial stage of spreading, single spread cells of 'normal' epithelial IAR 20 line) and cells with insufficient or no actin bundles (transformed fibroblastic L line) were prone to bending around a cylinder with much less pronounced elongation and orientation along its axis. The data obtained indicate that the reaction of cultured cells to the geometry of the substratum surface and, in particular, to a cylindrical surface is determined not only by the presence or absence of actin microfilament bundles but by their pattern in the cell.

Actins↗
PubMed1989

Distribution of platelets on flat substrata.

Rabbit platelets attached at a high density to flat glass were examined in a scanning electron microscope. Contours of neighbouring well-spread platelets were almost parallel to each other; overlapping of the edges of two cells were small and rare. Quantitative analysis has shown that overlappings actually observed were much smaller in area that those calculated on the basis of the assumption that platelets are randomly distributed on the substratum. Thus, contact inhibition of spreading is characteristic not only of nucleated cells but also of platelets.

Animals↗
PubMed1986

[Variants in the onset and development of the clinical manifestations of brain tumors].

A retrospective analysis of clinical manifestations of verified brain tumors in 1542 patients showed that the onset of the disease was acute in 5.8%, subacute in 12.3% and gradual in 81.9% while its further course was progressing in 60.5%, progression in 26.9%, remittent in 10.4% and even relatively stable in 2.2%. In 70.4% of the cases the brain tumor developed according to the classic "blastomatous" variant while in the remaining cases it developed atypically, i. e., as an inflammatory (13.1%) or vascular (10.7%) cerebral process, epilepsy (3.3%) or the syndrome of intracranial hypertension without focal symptoms (2.5%). or the syndrome of intracranial hypertension without focal symptoms (2.5%).

Adolescent↗
PubMed1981

Behaviour of normal and neoplastic rat cells on grooved substrates.

The distribution and shape of rat cells cultivated on plastic surfaces containing cylindrical areas of various radii and grooves of various depths were studied. Normal embryo cells and two lines of neoplastic cells (LW13K2 and RsK4) were used. The nuclear shape, orientation of the nuclei and migration of cells from the bottom of the grooves were assessed by quantitative methods. All characteristics of the behaviour of both neoplastic cell lines on the grooved substrates were found to be different from those of normal cells: a) the nuclei of neoplastic cells, in contrast to those of the normal ones, did not undergo additional elongation on the cylindrical areas of the substrate; b) the orientation of neoplastic cells with regard to the axis of the cylindrical substrate was decreased or absent; c) the migration of neoplastic cells from certain types of the grooves was decreased. It is suggested that the different reaction to the geometry of the substrate may be a characteristic feature of transformed cells. Possible mechanisms of these alterations are discussed.

Animals↗
PubMed1975

Quantitative evaluation of cell orientation in culture.

A quantitative method to assess mutual orientation of cells in cultures on a substrate includes the following operations: (1) the cellular groups to be evaluated are chosen; (2) position of the long axis for each nucleus of the group is determined; (3) the axis OX is arbitrary chosen for every group and the angles alphai between the long axis of every nucleus i and the axis OX are measured. Every nucleus i corresponds to a vector of unit length ei with the angles 2alpha. D, the mean of the vectors ei for every cell group is calculated. This value of D is compared with a set of values of D computed according to a model of mutual orientation studies in a simulation experiment. In this model the group of n vectors consists of a fraction of Kn parallel vectors (o less than or equal to K less than or equal to I) and of (I minus K)n randomly oriented vectors. K corresponding to the computed D which is equal to the experimental value of D is considered as an index of orientation for the group. Contact orientation with respect to the relief of the substrate may be evaluated as a root mean square deviation sigma0 to the angles between the long axes of cell nuclei and the direction of relief. Examples of the measurements of K and sigma0 in cell cultures are given.

Animals↗
PubMed1975

[A method of measuring cell orientation].

A method is described for measuring cell nuclei orientation in culture. The nuclear orientation in the experiment was compared with that obtained in the model experiment with electronic computer. The method developed allows to compare nuclear orientation in parts of culture which differ both by area and number of nuclei. The method can be modified for measuring cell nuclei orientation with reference to the substrate relief. Examples are given of the method's application for comparing orientation of mouse embryonic fibroblasts and cells of the strain L.

Animals↗