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Biomedical subjects

M Rozycka

Publications and source records attributed to M Rozycka.

At least 19 recordsLinked to original sources
PubMed1996

Membrane healing and restoration of contractility after mechanical injury in isolated skeletal muscle fibers of the frog.

In single isolated skeletal muscle fibers of the frog, we studied (i) the recovery from large sarcolemmal mechanical injuries of the response to electric stimulation and (ii) the integrity of the sarcolemma under the light microscope. In Ringer's solution, the damaged cells stopped contracting and deteriorated completely within 1 hr. In the presence of phosphatidylcholine (0.025 g/ml in Ringer's solution), the injured cells initially responded with local twitches. Within 0.5 hr, contractility and membrane integrity started to recover and both were back to control levels within 3 hr. When these cells were placed back in normal Ringer's solution, they remained viable and active for several hours. Our results suggest that phosphatidylcholine can protect muscle fibers from the effects of sarcolemmal injury.

Animals↗
PubMed1993

Non-homogeneous Ca release in isolated frog skeletal muscle fibres.

We have examined the spatial distribution of [Ca2+]i during tetanic stimulation in frog skeletal muscle cells using a fluorescence imaging method. We have found a completely unexpected pattern of Ca release: Ca is released forming gradients composed of spots of very significant and slow fluctuations of calcium release. Our findings could be explained if the calcium release process in skeletal muscle is influenced significantly by [Ca2+]i, such as in cardiac muscle, and suggests that the SR/Ca release control can include the established voltage-dependent plus a cardiac-like process of calcium-induced Ca release and a Ca release inhibition by Ca.

Animals↗
PubMed1991

Differential activation of myofibrils during fatigue in phasic skeletal muscle cells.

In fatigued muscles the T-system is swollen; thus the action potential may fail to travel along the T-system or the T-tubule terminal cisternae signal may fail to bring about TC Ca2+ release. This would lead to a decrease in the number of myofibrils activated and in force development, but if fatigue is the result of a generalized process, all the myofibrils would be affected equally leading to a lower activation of all of them. We have investigated this possibility in isolated twitch muscle fibres by giving them repetitive tetanic stimulations until fatigue developed. The behaviour of myofibrils was followed with cinemicrophotography. Before fatigue, no lack of shortening of myofibrils could be found. During fatigue groups of myofibrils became wavy. When exposed to caffeine, the wavy myofibrils disappeared and tension similar to the control developed. The tension-caffeine concentration relationship was shifted to the left after development of fatigue. In low Na+ solution fatigue developed faster and after reintroducing normal Ringer, tension recovered substantially. K-contractures were smaller during fatigue. These results indicate that in this type of fatigue, a step in the EC coupling chain of events is involved in its development.

Action Potentials↗
PubMed1991

Fourier analysis of the nuclear and cytoplasmic shapes of living two-cell murine embryos.

Living two-cell mouse embryos were flushed out from the oviduct 17, 24 and 36 hours after fertilization in order to obtain cells in the G1S, early G2 and late G2 phases of the second cell cycle. The nuclei of the living cells were stained with Hoechst 33342. The coordinates of the contour shapes of the entire cells (cellular contours) were registered by contour image processing with a TV camera coupled with a computer; the contours of the nuclei were computed by means of a digitizer coupled with the computer. Fourier analysis of the cellular and nuclear contours revealed systematic modifications in the folding of the cells and nuclei in the course of the murine second cell cycle. The progression of cells through the second cell cycle was correlated with an increasing diversification of cellular and nuclear shape, with the diversification being much more pronounced in the nuclear shapes.

Animals↗
PubMed1989

Heterogeneity of cytoplasmic and nuclear shape of lymphocytes during progression of chronic lymphocytic leukemia.

Peripheral blood from ten healthy subjects and from 44 patients at stages 0, I, II, III, IV of chronic lymphocytic leukemia (CLL), type B, was routinely smeared, fixed and stained by the May-Grunwald-Giemsa method. Fourier analysis of nuclear and cytoplasmic shape of smeared lymphocytes was carried out for the range 1-20 of harmonics (describing the pattern of contour folding in quantitative terms). In addition the roughness coefficients (describing the summarized measure of contour folding of an individual cell) were calculated and computer evaluated. Cytoplasmic contour shape of smeared lymphocytes in the 6-10 harmonic range discriminates well between lymphocytes of healthy subjects and those of each CLL stage. This discrimination was the result of richer folding of CLL lymphocytes. Nuclear contour shape of lymphocytes in the 6-10 harmonic range fails to discriminate between lymphocytes of healthy subjects and those of CLL, but it discriminates well between lymphocytes of various stages of CLL, with the exception of stages I/II and III/IV. When Fourier analysis was carried out on lymphocytes of combined stages I + II and III + IV, the shape differences were even more accentuated. We conclude that nuclear and cytoplasmic contour shape is a phenotypic feature of lymphocytes that is markedly modified in the course of CLL progression; this feature may be used as a new parameter in CLL.

Adult↗
PubMed1988

Effect of 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) and dichloromethylidene-bisphosphonate (Cl2MBP) on the structure of the organic matrix of heterotopically induced bone tissue.

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.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Analysis of chromatin pattern in blood lymphocytes of healthy donors and in lymphoid cells of patients with chronic lymphocytic leukaemia.

The optical Fourier transformation was used to analyse the chromatin/interchromatin pattern of lymphocytes of healthy subjects and lymphoid cells of patients with chronic lymphocytic leukaemia (CLL, type B, stage O). Peripheral blood smears were prepared routinely, fixed, and stained by the Feulgen method, and the photographic images of the nuclei were quantitatively analysed. From the radial distribution of light intensity of diffractograms, several Feulgen chromatin (F-chromatin/interchromatin) descriptors were evaluated. Four showed the strongest discriminant power and these descriptors discriminated well between lymphocytes of healthy donors and lymphoid cells of CLL patients, although F-chromatin/interchromatin components of the same sizes were found in lymphocytes and lymphoid cells.

Adult↗
PubMed1987

Fourier analysis of nuclear and cytoplasmic shape of blood lymphoid cells from healthy donors and chronic lymphocytic leukemia patients.

The folding rates of the contours of nuclei and entire lymphoid cells were analyzed by Fourier analysis of the shapes. Smears of peripheral blood from healthy subjects and from patients with chronic lymphocytic leukemia (CLL: type B, stage zero) were routinely prepared and stained. The shapes of lymphoid cells from CLL patients revealed a higher folding rate (from fifth to tenth harmonics) than did those of lymphocytes from healthy subjects. Accordingly, the roughness coefficient (describing the folding rate of the surface) for CLL cells was 0.036, as compared to 0.028 for the cells of healthy subjects. The shapes of nuclei of CLL lymphoid cells also had a higher folding rate than did those of lymphocytes from healthy subjects, but a significant difference was found only for the highest harmonic calculated (the tenth harmonic); the respective roughness coefficients for nuclei were 0.037 and 0.033.

Cell Nucleus↗
PubMed1986

Numerical evaluation of changes in the cytoplasmic microtubule complex of C3H mouse cells by optical diffractometry and of changes in cell shape by Fourier analysis.

MO mouse cells in culture on glass were treated with taxol, or nocodazole, or incubated at 4 degrees C to alter their cytoplasmic microtubule complex (CMTC). From each treated group and from an untreated group, 30 cells stained with an antiserum against tubulin, were photographed under the photomicroscope, and negatives were analysed by optical diffractometry. Differences between groups of cells were tested by variance analysis. Phase-contrast micrographs of the same cells were used for Fourier analysis of cell shape. Both types of analyses provided numerical objective data about changes in the CMTC and in cell shape that were typical for the kind of treatment. We conclude that optical diffractometry of immunostained cells and Fourier analysis of cell shape are complementary to photomicroscopy for the study of the CMTC in cell populations cultured on an artificial substrate.

Alkaloids↗
PubMed1986

Objective evaluation of fibrosis in human testicular biopsies by analysis based on optical diffractometry.

Bilateral testicular biopsies were obtained from 27 patients and submitted to two different treatments for each of them: firstly, a classical fixation and colouring, permitting the histopathological diagnosis and subjective appreciation of the degree of fibrosis; secondly, a new objective technique based on optical diffractometry: this method is based on the analysis of light intensity distribution in the diffraction pattern of an original image. Using two different methods of discriminant analysis, we observed some errors due to the subjective examination; in particular, several fibrosed samples had been judged as 'normal' by the histopathologist. Moreover, we showed the existence of some heterogeneity between different slides from the same original biopsy.

Biopsy↗
PubMed1984

Fourier analysis of the shape of normal and transformed epithelial cells derived from human transitional epithelium.

The aim of this paper is to show the possibility of objective mathematical description of changes occurring in the shape of cells in the process of transformation. The evaluation of the changes in cell shape of the chosen cell lines differing in transformation grade was performed by the use of Fourier analysis of the shape. Any two-dimensional contour can be described with specific accuracy in a mathematical manner using the closed form Fourier series of cosines. The components forming the analysed shape, called harmonics, are independent and uncorrelated measures of their contribution to the total shape. The shape of each cell can be represented by the spectrum of harmonic amplitudes. To quote the paper by Healy-Williams and Williams (1981): "The observed shape is partitioned into series, where gross shape, as elongation or triangularity, is measured by the harmonic amplitudes of the lower harmonic order and increasingly fine scaled surface sculpture is measured at higher orders". The statistically evaluated results allow the objective comparison of the cell shapes of several compared cell lines differing in transformation grades. Malignant transformation is supposed to be a multistep process. The different grades of transformation could be defined by several parameters as changes in the morphology of the cells, their ability to compete with fibroblasts, their life span, their angiogenic potency, their invasiveness in vitro and their tumorigenicity in nude mice. In this paper several human urothelial cell lines of normal and tumor origin differing in their transformation grade (TGr I-III) were compared by the use of Fourier analysis of their shape. TGr I cultures have finite life span but do not need intermittent collagenase treatment to prevent fibroblast overgrowth. TGr II cultures acquire infinite growth potential, here defined as capacity to survive at least 70 passages. They are neither tumorigenic nor invasive. TGr III cultures show infinite growth transformation, increased angiogenicity and ability to invade normal host tissue in vitro. They produce progressively growing tumors in nude mice. The following human uroepithelial cell lines differing in the degree of transformation were studied and compared by statistical evaluation of the harmonic amplitudes describing mathematically the cell shape: Two cell lines derived from human transitional cell carcinoma (TCC): 1. Hu 1703S classified as TGr I, 2. Hu 1703He classified as TGr III. It was found that these two cell lines differ in all harmonics. Two cell lines derived from morphological normal human bladder epithelium: 3. HCV-29 classified as TGr II.(ABSTRACT TRUNCATED AT 400 WORDS)

Carcinoma, Transitional Cell↗
PubMed1983

Application of optical diffractometry in studies of cell fine structure. Comparison of arterial smooth muscle cells in contractile and synthetic state.

Arterial smooth muscle cells in contractile and synthetic state were analyzed by optical diffractometry. Cell sections (80-90 nm) were photographed in an electron microscope and diffraction patterns of the plates (negatives) were produced using a helium-neon laser. Radial and angular distributions of light intensity in the diffractograms were measured and digitized using an electronic detector plate consisting of ring- and wedge-shaped photosensitive elements; radial distributions provide information about size of structures and distances between them and angular distributions about spatial orientation of structures in the images. Micrographs of nuclei and cytoplasm were analyzed separately (40-50 plates in each group). Computerized statistical analysis of radial distributions of light intensity showed that the nuclear chromatin pattern differed between cells in contractile and synthetic state. The probability that the observed difference could have arisen purely by chance was less than 10(-5). Computer-aided classification to the a priori known cell group was correct in 96.5% of the cases. Analysis of radial distributions of light intensity similarly showed marked differences in cytoplasmic structure between cells in contractile state (dominated by bundles of myofilaments) and synthetic state (dominated by cisternae of rough endoplasmic reticulum). The probability that the observed difference could have arisen purely by chance was less than 10(-5). Computer-aided classification to the a priori known cell group was correct in 92.0% of the cases. In contrast, analysis of angular distributions of light intensity did not indicate any statistically significant differences between contractile and synthetic state cells. A likely reason is that both myofilaments and cisternae of rough endoplasmic reticulum were arranged in parallel. The results demonstrate that optical diffractometry is a useful method for image analysis in studies of cell fine structure. It provides information about size and orientation of structures with poorly defined shape and is particularly well suited for studies on cell differentiation and effects of pharmacological and other experimental treatments on cell fine structure. It represents an alternative and a complement to stereology for quantitative and objective evaluation of morphological data.

Animals↗
PubMed1982

Application of the optical Fourier transform for analysis of the spatial distribution of collagen fibers in normal and osteopetrotic bone tissue.

Optical Fourier analysis was applied for evaluation of the differences between normal and pathologically changed bone tissue. Collagen fibers were used as markers of bone structure. To prove the usefulness of this technique for objective mathematical analysis of these differences the spatial spatial distribution of collagen fiber bundles was evaluated in normal and osteopetrotic bone. The variation in the spatial distribution of collagen fiber bundles in cross sections of femur diaphyses was evaluated quantitatively by optical diffraction three groups of Fatty Orl-op strain rats, i.e. phenotypically normal animals, osteopetrotic (op/op) mutants and op/op-mutants cured by transplantation of normal syngenic bone marrow. The histological sections of decalcified bone were stained with Sirus-Red and then photographed under polarizing microscope. The Sirus-Red staining was used to enhance the natural birefringency of collagen fibers. Diffractograms obtained from microphotographs of selected bone section areas, i.e. outer and inner circumferential lamellae and haversian bone of normal and cured op/op animals as well as whole cortical bone and woven bone filling the medullary cavities in op/op mutants were analysed separately. Diffractograms contain summarized information on the size and relative position of these structures in histological sections. The radial and angular distribution of light energy were evaluated for each diffractogram with an electronic detector. The obtained distributions were described by several sets of parameters concerning the position, level and shape of local maxima and minima. Out of these parameters five with the highest discriminant power were chosen for further mathematical analysis. This analysis was based on the calculation of the position of centroids in the multidimensional space described by the linear functions of the chosen parameters for each of the evaluated bone section areas. The centroids (mean values of discriminant scores of each group) represent the centers of gravity of the analysed groups, while the separation of the centroids tested by the F-test illustrates the differences between the respective groups of selected bone section areas. A high level of separation of centroids was found when osteopetreotic bone was compared with normal one, what means that the spatial distribution, size and interstructural distances between the collagen fiber bundles in bone tissue in these two groups of animals differ markedly. A similar situation was observed when osteopetrotic bone was compared with bone tissue obtained from op/op mutants cured by transplantation of normal syngenic bone marrow. On the other hand, the level of separation of centroids was low when bone tissue of cured op/op mutants was compared with the control one, a finding which corresponds to the less pronounced histological differences between these two groups of animals. Computer-aided classification on single microphotographs of selected bone section areas to the known a priori type of bone tissue was performed...

Animals↗
PubMed1982

Polarizing microscopy of Picrosirius stained bone sections as a method for analysis of spatial distribution of collagen fibers by optical diffractometry.

Cross sections of femur diaphysis obtained from control and osteopetrotic rats were stained with hematoxylin-eosin (HE) and Picrosirius (SR). Analogous selected areas of bone sections photographed under a polarizing microscope were analysed by optical diffractometry. Since the collagen fibers are a good marker for the structure of bone tissue, their spatial distribution evaluated by optical diffractometry provides information on the tissue architecture. The Picrosirius staining technique enhances the natural birefringency of collagen fibers. Therefore, in the polarizing microscope, pictures of high contrast are obtained. This procedure, by increasing the amount of information in the image, increases the quantity of the data obtained by optical diffractometry in comparison with the HE staining method. The results obtained prove that SR staining combined with polarizing microscopy might be useful for optical diffractometry in analysis of the spatial distribution of collagen fibers in all connective tissues, where they could serve as markers of tissue architecture.

Animals↗