Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 10

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1

Surface anisotropy orients cell divisions in contact guided cells

100%
Krzysiek-Maczka G., Korohoda W.
Folia Biologica
|
2008
|
vol. 56
|
issue 1-2
13-19
EN
The orientation of cell elongation and the plane of cell division were determined in cells growing under isotropic conditions on a plain glass surface or under anisotropic conditions on a scratched glass surface. Four cell lines were analysed, each showing various degrees of contact guidance. Human skin fibroblasts and the skin keratinocyte cell line HaCaT oriented randomly on the smooth isotropic surface of glass, grew and divided randomly. By contrast, on an anisotropic scratched surface these cells showed contact guidance, elongated along scratches, and their planes of division were perpendicular to the long axis of the cell. In these two cell types there was a high degree of correlation between the cell alignment and the plane of cell division, which shows that extracellular factors can influence or even determine the latter. In cell lines in which contact guidance under anisotropic conditions was less evident, viz. the lung endothelial cell line HLMEC and the skin endothelial cell line HSkMEC, the alignment of cell division planes was less ordered. This report concentrates on quantitative phenomenological descriptions of the orientation of cell division as determined by contact guidance.
2

Motile activities of Dictyostelium discoideum differ from those in Protista or vertebrate animal cells

81%
Waligorska A., Wianecka-Skoczen M., Korohoda W.
Folia Biologica
|
2007
|
vol. 55
|
issue 3-4
87-93
EN
Cell movement in the amoebae Dictyostelium discoideum has been examined in media differing in monovalent cation concentration (i.e. Na+ and K+). Under isotonic or even slightly hypertonic conditions, the cells move equally well in solutions in which either potassium or sodium ions dominate. However, in strongly hypertonic solutions the amoebae showed motility in a 2% potassium chloride solution, but remained motionless in a hypertonic 2% sodium chloride solution. This inhibition of D. discoideum amoebae movement in a hypertonic sodium chloride solution was fully reversible. Such behaviour corresponds to that of plant, fungi, and some invertebrate animal cells rather than protozoan or vertebrate cells. These observations suggest that studies using D. discoideum as a model for cell motility in vertebrate animal tissue cells should be considered with caution, and would seem to confirm the classification of cellular slime moulds as related rather to Fungi than to Protista. This also shows that the cell membrane models should consider the asymmetry in sodium /potassium ion concentrations found in vertebrate animal cells as one of various possibilities.
3

Morphometric analysis of LPS-stimulated human monocytes by computer-assisted image analysis

81%
Madeja Z., Kupiec M., Korohoda W.
Folia Biologica
|
1998
|
vol. 46
123-128
EN
This report describes the results of applying the computer-assisted image analysis system for the measurement of some cytological parameters of LPS-stimulated and nonstimulated human monocytes. The experiments were carried out by means of the digital cell image analysis of haematoxilyn stained monocytes. Five different parameters describing the morphology of monocytes and their nuclei were selected to quantitate the differences between control and activated cells: area, perimeter, elongation, dispersion, and extension of images of cell projections. The results suggest that all of the analysed parameters can be used to discriminate stimulated from nonstimulated monocytes which permits detailed monitoring of the changes in cell morphology during monocyte activation.
4

Involvement of cytoskeleton in orientation of cell division in contact guided cells

81%
Krzysiek-Maczka G., Michalik M., Madeja Z., Korohoda W.
Folia Biologica
|
2010
|
vol. 58
|
issue 1-2
21-27
EN
Single human skin fibroblasts and the skin keratinocyte cell line HaCaT show contact guidance and elongate along narrow (1-2 Fm) scratches in glass substratum. During cell division these cells orientate their mitotic spindles along the long axis of the cell. Immunofluorescence staining of actin, tubulin, chromatin, and the nuclear NuMA protein complex demonstrated that cell elongation along scratches is accompanied by a corresponding rearrangement in the cytoskeleton. The results and literature suggest the following steps in the interplay between outside-in and inside-out signalling in the regulation of cell division orientation by extracellular factors. The interaction of cell surface with an anisotropy in the local environment causes changes in F-actin organization, cell elongation and alignment of stress fibres along the cell axis. This is accompanied by a corresponding reorientation of microtubules. Microtubules mediate between cell shape changes dependent upon cell interaction with substratum or other cells, the cortical actin and the position of centrosomes. Centrosomes determine the position and orientation of the mitotic spindle. The astral and central microtubules of the mitotic spindle control the localization of contraction-relaxation in the cell cortex and the position of the constriction ring and cell division plane.
5

Some difficulties in research into cell motile activity under isotropic conditions

81%
Waligorska A., Wianecka-Skoczen M., Nowak P., Korohoda W.
Folia Biologica
|
2007
|
vol. 55
|
issue 1-2
9-16
EN
Movement of Dictyostelium discoideum amoebae under isotropic and anisotropic conditions was recorded and analysed with computer-aided methods and the results are presented in various manners as described in the subject literature. Cell movement under isotropic conditions showed great diversity. Some cells moved almost in a straight path whereas others in close proximity turned around with little net translocation. When cell movement under isotropic conditions was observed, no direct correlation was found between the total length of cell trajectories and the length of final displacements of the cells. It was necessary to present the results in the form of histograms, circular diagrams of cell trajectories or in scatter correlation diagrams showing the motile behaviour of many individual cells. These methods of presentation are more informative than methods which present only average values, the 'representative' behaviour of single cells, or start and end points of cell tracks. The latter methods can only illustrate but do not document the results of experiments. The use of statistical methods appears necessary in cases when it is difficult to monitor the same cells before and during experimental treatment. However, when cell movement under anisotropic conditions becomes oriented and ordered as during tactic cell movements, then the diversity in cell behaviour decreases and methods based on estimation of starting and end points of cell positions appear more credible.
6

Anchorage-dependent chick embryo fibroblasts synthesise DNA and proliferate when cultured in multilayered sheets suspended among glass fibres

81%
Czyz J., Dobrucki J., Korohoda W.
Folia Biologica
|
2001
|
vol. 49
|
issue 1-2
1-12
EN
Chick embryo fibroblasts (CEFs) spontaneously form multicellular and multilayered sheets suspended on the network of glass fibres which are stabilized by fibronectin containing protein deposits located at cell-to-cell contacts. The cells situated within the sheets are surrounded by the neighbouring cells and their mechanical equilibrium is stabilised by intercellular ?parabaric? effects. It was found that CEFs in the sheets retain relatively high mitotic activity corresponding to that observed in sparse monolayer cultures. These cells grew up to much higher local density than in confluent and contact-inhibited monolayer cultures and developed an abundance of microfilament bundles that terminated at vinculin-containing protein complexes. The results presented demonstrate that direct contact with solid substratum, cell-to-cell contacts, local cell density, and intercellular exchange of humoral factors are not directly involved in the density-dependent inhibition of growth observed in monolayer cultures. They also support the concepts concerning the role of mechanical equilibrium of cell membrane and sub-membranous cytoskeleton in the regulation of proliferation of non-transformed cells.
7

Reversible inhibition of movement in the amoebae Dictyostelium discoideum and its effect on chemoattractant recognition

81%
Waligorska A., Wianecka-Skocze? M., Korohoda W.
Folia Biologica
|
2008
|
vol. 56
|
issue 3-4
123-133
EN
The cell fixatives formaldehyde and KMnO4 at low concentrations reversibly inhibit the movement of D. discoideum amoebae without directly interfering with cell viability. This inhibition of cell movement is accompanied by the decreased attachment of cells to substratum.When the tenacity and attachment of immobilized cells are artificially increased by compressing cells between two glass surfaces, the amoebae begin to move even in the presence of the fixatives. Amoebae starved for 24 hours, subjected to fixatives and a mineral salt solution in which they remained motionless, maintained chemotactic res acid and only after a few hours of active locomotion became reactive to cAMP.
8

Spreading-independent growth of normal fibroblasts in three-dimensional cultures

71%
Czyz J., Rajwa B., Bzowska M., Dobrucki J., Korohoda W.
Folia Biologica
|
2004
|
vol. 52
|
issue 1-2
19-24
EN
Changes of cell shape resulting from cellular flattening on culture substratum have previously been demonstrated to correlate with mitotic activity of normal animal cells in monolayer cultures. Here, we compared the shapes and proliferation of chick embryo fibroblasts cultured either in multicellular, multilayered sheets extended between glass fibres, or in standard monolayers. Fibroblasts in sheets retained the mitotic activity characteristic of that observed in sparse monolayer cultures, i.e. considerably higher that in confluent monolayers. Morphometric analyses revealed, however, that the cells in sheets were considerably less flattened than in monolayer cultures. These observations indicate that the modulation of culture conditions resulting in multidirectional cell stretching leads to the dissociation of flattening and mitotic activity of normal animal cells, so long as an intracellular stress field, generated by contractile cytoskeleton and stabilised by intercellular contacts, is maintained.
9

Comparison of proliferation and motile activity between human keratinocytes isolated from skin and oral muco

62%
Drukala J., Zarzecka J., Gojniczek K., Waligorska A., Zapala J., Korohoda W.
Folia Biologica
|
2005
|
vol. 53
|
issue 1-2
21-28
EN
Objective: Epithelial wound repair assures the recovery of the epithelial barrier after wounding. During wound healing epithelial cells migrate to cover the wound surface. For healing of skin wounds the skin keratinocytes can be replaced by oral mucosa epithelial cells grown in vitro. The presented experiments were carried out in order to compare the proliferation, morphology, and migration between human keratinocytes isolated from human skin and oral mucosa. Materials and methods: Human epidermal and oral mucosa keratinocytes from primary culture were used in all experiments. Cell motility and shape were determined using computer-aided methods. Results and conclusions: It was demonstrated that although both cell types exhibit the same typical epithelial morphology, oral mucosa keratinocytes locomote significantly faster than skin keratinocytes. They also differ in proliferation activity. Oral mucosa keratinocytes exhibited faster growth and different actin cytoskeleton organisation than skin keratinocytes under in vitro conditions. Autologous oral mucosa keratinocytes may be expanded in vitro and used for skin wound healing in vivo.
10

Morphometric analysis of pancreatic carcinoma by computer-assisted image analysis

62%
Wolnicka A., Foryst A., Madeja Z., Tomaszewska R., Walter R., Stachura J., Korohoda W.
Folia Biologica
|
1998
|
vol. 46
7-15
EN
This report describes the results of applying the interactive image analysis system for the measurement of some cytological parameters corresponding to features of adenocarcinoma of the pancreas. The present experiments were carried out by means of the digital cell image analysis of haematoxilyn and eosin stained archival standard glass slides of cancer bearing and healthy patients. Four different parameters describing the morphology of nuclei and nucleoli were selected to quantitate the differences between control and malignant tissues: area, perimeter, elongation, and extension. The parameters that showed the greatest differences between cancerous and normal pancreas were: area and elongation in the case of nuclei as well as area and perimeter for nucleoli. However, the results of this study suggest that none of the four analysed parameters can be selected alone to discriminate neoplastic from normal cells, but could be used all together in diagnosis of pancreatic cancer.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.