ALBERT

Notes: Summary In order to evaluate in mathematical terms the morphological changes occurring in the course of cell spreading, Fourier analysis of shape was applied. Human urothelial Hu 961 b cells plated on type IV collagen, fibronectin, laminin, glass and bovine serum albumine (BSA) were studied. Fourier parameters describing cell shape as well as surface areas covered by the cells on the substrate were subjected to statistical analysis. Using analysis of variance and discriminant analysis it was found that parameters describing cell shape (both gross shape of cells and their fine scale contour foldings) possessed a higher power of discrinunation between the cells spread on various substrates than the differences in cell surface areas. In the course of observation (75 and 150 min) the highest number of attached cells and highest degree of spreading were found when cells were plated on type IV collagen. Moderate alterations in cell shape and moderate increase of surface area were seen in the group of cells seeded on fibronectin, whereas the cells plated on laminin, glass and BSA revealed a moderate increase of surface area, but no changes in their shape were observed. The differences in attachment of cells and in the degree of their spreading might be due to the variation in expression of plasma membrane receptors for various substrates. The Fourier analysis of cell shape coupled with measurement of surface area is a good tool for quantitative evaluation of cell spreading and can be used for discrimination between cells spread on different substrates.

Notes: Summary The effect of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) and dichloromethylidene-bisphosphonate (Cl2MBP) on the structure of the organic matrix of heterotopically induced bone in guinea pig was studied. Heterotopic bone formation was induced by transplantation of allogenic urinary bladder epithelium. Starting from the day of transplantation the animals were treated subcutaneously with HEBP and Cl2MBP with a dose of 12.5 mg P/kg/day during 35 days. The control group was injected with 0.9% NaCl solution. The advantage of heterotopic bone induction as an experimental model is the fact that the applied drugs act on de novo bone formation. Collagen fibers were treated as markers of bone because their size and spatial arrangement reflect the structure and maturity of organic matrix of this tissue. Decalcified histological sections of induced bone, taken 35 days after implantation of inductor, were stained by the picrosirius method. This staining enhances the natural birefringency of collagen fibers and allows for better and specific visualization of collagen fibers bundles under polarizing microscope. In this way the amount of information in the analysed image is increased. Thirty five microphotographs were analysed from each of the investigated groups with the use of optical diffractometry. The radial distribution of light intensity in diffraction patterns was analysed what allowed to evaluate spatial frequencies connected with the width of collagen bundles in induced bone tissue. Since the spatial arrangement of collagen fibers in newly formed bone is random, analysis of angular distribution of light intensity in diffractograms was not performed. Using discriminant analysis the significant differences between all three studied groups of animals were found. The widest differences were found between the Cl2MBP and HEBP treated animals. They were larger than those between each of these two groups and the control one. In control as well as in HEBP treated animals thicker bundles of collagen fibers were more frequently observed than in the Cl2MBP treated group, while in the latter thin bundles, nondetected in the former two groups were found. Generally, the radial distribution of light intensity in diffraction patterns of the HEBP treated animals resembles more that in the control group than in the Cl2MBP treated one. The different effects of the two analysed bisphosphonates (BPs) on the organic bone matrix of heterotopically induced bone is interpreted as differences in their influence on osteogenic cells and/or as differences in their direct influence on extracellular collagen fiber bundles formation.

Notes: Summary The rationale of the present investigation is the observations made by many authors of changes in the molecular structure of the cell surface during the multistep process of malignant transformation. These changes may influence cell-matrix and cell-cell interactions and thereby cause changes in cell adhesiveness and cell shape. The aim of the present work was to investigate whether the development of various grades of transformation in vivo and in vitro of human urothelial cells is accompanied by significant changes in cell shape as measured by Fourier analysis. The following transformation grades (TGr) have been defined (Christensen et al. 1984; Kieler 1984): TGr I=nonmalignant, mortal cell lines that grow independently of fibroblasts and have a prolonged life span. TGr II=nonmalignant cell lines with an infinite life span. TGr III=malignant and immortal cell lines that grow invasively in co-cultures with embryonic chick heart fragments and possess tumorigenic properties after s.c. injection into nude mice. Comparisons of 4 pairs of cell lines were performed; each pair was of the same origin. Two pairs-each including a TGr I cell line (Hu 961b and Hu 1703S) compared to a TGr III cell line (Hu 961a or Hu 1703He)-were derived from two transitional cell carcinomas (TCC) containing a heterogeneous cell population. Two additional cell lines classified as TGr II (HCV-29 and Hu 609) were compared to two TGr III sublines (HCV-29T and Hu 609T, respectively) which arose by “spontaneous” transformation during propagation in vitro of the respective maternal TGr II-cell lines. One of these TGr II cell lines (HCV-29) originated from the histologically normal bladder mucosa obtained from a patient with a previous history of bladder papillomata treated with irradiation (Fogh, personal communication). The other TGr II cell line (Hu 609) was derived from the normal ureter of a patient with renal carcinoma. In each of these 8 cell lines, the shape of 100 cells chosen at random were subjected to Fourier analysis of shape. Each of the particular harmonic amplitude values studied was used as an individual parameter for the evaluation of differences between compared cell lines, using Chi-Square test and discriminant analysis. It was found that in two of four analysed pairs of cell lines, i.e. Hu 1703S (TGr I) vs Hu 1703He (TGr III) and HCV-29 (TGr II) vs HCV-29T (TGr III), the differences in cell shape between the two populations were very well pronounced, as was shown by several statistical parameters. In the two other pairs of cell lines, i.e. Hu 961b (TGr I) vs Hu 961a (TGr III) and Hu 609 (TGr II) vs Hu 609T (TGr III) significant differences in cell shape were also found, but they were less pronounced. The conclusion is, that differences in cell shape in vitro may reveal the cellular heterogeneity of the original transitional cell carcinoma and/or the progression of in vitro propagated urothelial cells from one grade of transformation into another.

Notes: Abstract Layers of conductive oxide powders (IrO2, RuO2 and Bi2Ru2O7) were prepared on alumina substrates by a thick-film technique. The films were fired at 875° C for different dwell times. The temperature dependence of resistance was measured in the range −196 to 850° C. SEM observations of the initial powders and the resistive layer surface after firing, as well as X-ray diffraction investigations, were carried out. The RuO2 and IrO2 oxides exhibit a high sintering ratio and the resistance of the fired layers increases with temperature as in the single crystal. The R(T) curve for Bi2Ru2O7 layers is in qualitative agreement with the polycrystalline material. The role of the grain surface area and the regions between the grains is dominant.