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Biomedical subjects

S Moskalewski

Publications and source records attributed to S Moskalewski.

At least 37 records · Page 2Linked to original sources
PubMed1991

Difference in size of bone islands formed by isolated bone cells transplanted intramuscularly under various conditions.

Bone cells isolated from the whole calvaria (2 x 10(6)) from either central or peripheral parts of parietal bones (1 x 10(6)) and from scapulas (2 x 10(6)) were allowed to adhere to devitalized calvarial bones in the number indicated in brackets and transplanted intramuscularly (supported transplants). Whole calvaria bone cells (2.4 or 8 x 10(6) cells per transplant) were also injected intramuscularly as free transplants. Calvarial cells produced solid bone islands with small intraosseous cavities, while bone formed by scapular cells contained large medullary spaces. The size of bone islands formed in transplants and the shortest distance between the neighbor islands were measured. The results of these measurements were similar in all groups of free transplants. The size of bone islands formed in supported transplants of cells from the whole calvaria or from central and peripheral parts of parietal bones was also roughly similar, but the shortest distance between islands was larger than in the free transplants. Furthermore, in these groups of transplants bone islands considerably larger than the largest islands in free transplants were present. Scapular bone cells formed islands much larger than those produced by calvarial cells. Bone islands formed by calvarial cells in free transplants were separated by bands of fibrous tissue which was absent in supported transplants. It appears that this tissue could limit growth and/or fusion of neighbor bone islands and in this manner influence their size. The population of transplanted scapular cells contained numerous stromal elements which could form an exclusion area inaccessible to local cells from the site of transplantation and thus favour formation of large bone islands within this area.

Animals↗
PubMed1991

Effect of immunosuppression on rejection of cartilage formed by transplanted allogeneic rib chondrocytes in mice.

The effect of short-term immunosuppressive treatment with antithymocyte serum-procarbazine (ATS-PCH) and cyclosporin-A (Cy-A) on survival of allogeneic rib chondrocyte grafts was examined morphologically and by evaluation of specific humoral and cellular antigraft immunity. The latter were evaluated by means of leukoagglutination and the indirect migration inhibition assay, respectively. Untreated recipients of syngeneic rib chondrocytes and untreated recipients of whole syngeneic and allogeneic rib cartilage served as controls. Transplanted syngenic rib chondrocytes formed cartilaginous nodules similar to rib cartilage in situ. These nodules contained hypertrophied chondrocytes, but neither physiologic resorption by vascularized connective tissue nor bone formation occurred after an observation period of longer than six weeks. Transplantation of allogeneic chondrocytes resulted in development of humoral and cellular antigraft immunity, and the formed cartilage was destroyed by infiltrating immune cells. Immunosuppression by ATS-PCH resulted in inhibition of graft destruction and a marked decrease of specific humoral antigraft immunity. Cellular antigraft immunity did not occur. Moreover, neither the histologic appearance of the cartilaginous nodules nor the results of immunologic response evaluations in the ATS-PCH-treated group differed from those in untreated whole allogeneic cartilage recipients. Treatment with Cy-A did not significantly improve survival cartilage formed by allogeneic chondrocytes.

Animals↗
PubMed1991

Transplantation of isolated chondrocytes.

Intramuscular transplantation of isolated syngeneic chondrocytes from hyaline and elastic cartilage results in formation of cartilage with various degrees of similarity to the original tissue. Cells from cartilage with a simple structure, such as nasal septal cartilage, form islands of tissue with flattened chondrocytes at the periphery and more rounded ones in the center. Chondrocytes from auricular (elastic) cartilage taken from young animals produce islands of tissue with an arrangement of cells and fibers similar to that of the material used for isolation of chondrocytes. Cartilage produced by elastic chondrocytes from older animals has an irregular arrangement of cells and contains fewer elastic fibers than cartilage produced by chondrocytes of corresponding age in situ. Chondrocytes from epiphyseal cartilage produce tissue with an irregular arrangement of cells, but nevertheless, are treated with endochondral ossification. Transplants of allogeneic chondrocytes evoke a strong immune response in the recipient. Such chondrocytes produce cartilage that is surrounded and slowly resorbed by infiltrating cells and does not ossify. Short-term immunosuppression (procarbazine and antithymocyte serum) prevents rejection of such cartilage and allows endochondral ossification.

Animals↗
PubMed1990

Disorganization and reorganization of the Golgi complex and the lysosomal system in association with mitosis.

The fate of the Golgi complex and the lysosomal system during mitosis was studied in L929 mouse fibroblasts by staining with wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) and transmission electron microscopy. In interphase WGA-HRP stained a circumscribed juxtanuclear region encompassing the stacked Golgi cisternae, the trans Golgi network, secretory vacuoles, endosomes, and lysosomes. As the cells entered prophase, WGA-HRP reactive material was spread around the perimeter of the nucleus. Fine structurally, the Golgi complex was found to be disorganized and its stacks were scattered throughout the cytoplasm together with clusters of lysosomes. At the same time, the trans Golgi network atrophied and secretory vacuoles and endosomes decreased in number. The disperse and structurally modified state of the Golgi complex and the lysosomal system persisted until late telophase, when they were reorganized in a defined region, most frequently on the outside of the nucleus as related to the midbody. The disorganization and reorganization of the Golgi complex and the lysosomal system coincided with the breakdown and rebuilding of the microtubular cytoskeleton, and showed striking similarities to the previously described modifications of these organelles during treatment with and after withdrawal of microtubule-disruptive drugs. Based on the findings, a model is presented that links the division of the Golgi complex and the lysosomal system to the loss of the radiating array of interphase microtubules.

Animals↗
PubMed1990

Comparison of bone formed in transplants of isolated scapular and vertebral osteoblasts.

To compare the properties of osteoblasts from various endochondrilia bones, scapular and calvarial osteoblasts were intramuscularly transplanted in "sandwiches" made of devitalized calvarial vaults. The structure of transplants produced by both types of bone cells appeared similar. In 4 week-old transplants woven bone with numerous osteoclasts predominated. The area occupied on the cross-sections of transplants by bone tissue was considerably larger than that of the bone marrow cavities. Transplants of 8-week-duration contained mainly cancellous bone, the number of osteoblasts was low and the area taken by medullary space was larger than that of bone tissue. This finding indicates that either osteoblasts from various endochondrlia bones have similar properties or that the possible differences in intrinsic features of these osteoblasts were masked by the conditions of transplantation.

Animals↗
PubMed1990

Cartilage transplants in normal and preimmunized mice.

Syngeneic, H-Y incompatible and allogeneic rib and nasal cartilages from 5-day- and 8-week-old mice were transplanted into adult recipients. Some recipients of allogeneic transplants were preimmunized with splenocytes or chondrocytes from animals of the same strain as cartilage donors, and some with sheep red blood cells (SRBC). Syngeneic or allogeneic transplants independently of the age of the cartilage, did not evoke any detectable humoral or cellular response as judged by evaluation of the specific cytotoxic antibodies and indirect migration inhibition test, respectively. Allogeneic transplants of nasal cartilage were free of infiltrating lymphoid cells, but in the vicinity of rib cartilage grafts some lymphocytes were present. Animals preimmunized with allogeneic splenocytes or chondrocytes displayed both humoral and cellular response to donor cells. Allogeneic cartilage transplants from these animals were surrounded by heavy infiltrations. Preimmunization with SRBC did not evoke infiltrations around allogeneic cartilage grafts.

Age Factors↗
PubMed1989

Bone formation following intrarenal transplantation of isolated murine chondrocytes: chondrocyte-bone cell transdifferentiation?

Isolated syngeneic epiphyseal chondrocytes transplanted into a muscle formed cartilage in which matrix resorption and endochondral ossification began at the end of the second week after transplantation. After 56 days cartilage was converted into an ossicle. In 7-day-old intrarenal transplants, epiphyseal chondrocytes formed nodules of cartilage. In 10-day-old transplants, islands of bone appeared. Slight resorption of cartilage was first noted in 14-day-old transplants of chondrocytes. After eight weeks, transplants contained mainly bone. Intramuscularly transplanted rib chondrocytes formed cartilage which did not ossify. Nevertheless, bone islands appeared in intrarenal transplants of rib chondrocytes. Bone was not formed in allogeneic intrarenal transplants of epiphyseal or rib chondrocytes, but appeared in such transplants in animals immunosuppressed by anti-thymocyte serum and procarbazine. When spleen cells from animals immunized with allogeneic chondrocytes were transferred to immunosuppressed chondrocyte recipients two weeks after intrarenal chondrocyte transplantation, the majority of osteocytes in bone islands was dead. On the other hand, endochondral bone formed in intramuscular transplants of allogenic epiphyseal chondrocytes in immunosuppressed recipients was not damaged by sensitized spleen cells. This suggested that bone in 10- to 14-day-old intrarenal transplants of chondrocytes arose from injected cells and not by induction. To see whether bone was formed by chondrocytes or by some cells contaminating the chondrocyte suspension, the superficial layer of rib cartilage was removed by collagenase digestion and only more central chondrocytes were used for transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Hoechst 33342 staining coupled with conventional histological technique.

Hoechst 33342 was injected either intravenously or intraperitoneally into mice which were killed 1 or 24 hr or 7, 14 or 28 days later. Various organs were fixed and paraffin embedded. Visual inspection showed that independently of the route of dye administration or survival time, distinct fluorescence of nuclei was observed in organs other than cerebral cortex. Even formic acid decalcification of bone failed to abolish the fluorescence of osteocytes. In vivo staining with Hoechst 33342 is proposed as an alternative for staining after sectioning. Cells from spleens of Hoechst 33342-injected mice or stained in vitro were injected intramuscularly into mice. Hoechst 33342-stained splenocytes could be found in deparaffinized sections at the site of injection 24 hr later.

Animals↗
PubMed1989

Difference in shape of bone formed by isolated calvarial and scapular osteoblasts transplanted under various conditions.

To study the influence of transplantation conditions on early stages of osteogenesis, isolated calvarial or scapular osteoblasts were injected into the leg or dorsal muscles (free transplants) or implanted after seeding on fragments of devitalized parietal bones (supported transplants) into dorsal muscles. The cross-sections of bone islands formed by calvarial osteoblasts in the different types of transplants were then compared according to their maximal breadth and length. Moreover, the same dimensions of pieces of bone formed by scapular osteoblasts in supported transplants were compared with those of bones formed in free transplants into leg muscles. Finally, comparison of the dimensions of cross-sections of supported transplants of calvarial and scapular osteoblasts was done. Calvarial osteoblasts in dorsal muscles produced a slightly higher percentage of wider and longer islands than those in leg muscles. In supported transplants of calvarial osteoblasts the percentage of narrow bone islands (breadth less than 100 microns) was considerably higher than in free transplants. Similarly, the percentage of narrow cross-sections in bones formed by scapular osteoblasts was higher in supported than in free transplants. In supported transplants of calvarial osteoblasts the percentage of narrow islands was higher than in similar transplants of scapular bone cells. It is suggested that the differences in shape of pieces of bone formed in supported and free transplants reflect the difference in mechanical conditions to which the bone cells were subjected. Furthermore, in supported transplants devitalized parietal bones could form a barrier for diffusion of nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Subpopulations of microtubules with differential sensitivity to nocodazole: role in the structural organization of the Golgi complex and the lysosomal system.

The role of cytoplasmic microtubules (MTs) in the structural organization of the Golgi complex and the lysosomal system was studied in L929 mouse fibroblasts using a combination of cytochemical and electron microscopic methods. Immunocytochemical staining demonstrated a radiating pattern of MTs, originating in the juxtanuclear region containing the centrioles. The stacks of Golgi cisternae with associated vesicles and tubules (the trans Golgi network), as well as most of the endosomes and lysosomes, were also located in and immediately around this region. Wheat germ agglutinin (WGA) conjugated to horseradish peroxidase (HRP) bound to the plasma membrane at 4 degrees C. After warming to 37 degrees C, the conjugate was rapidly internalized by endocytosis and via small vesicles transferred to endosomes and lysosomes in the juxtanuclear region. Slightly later it was also found in the trans Golgi network. A weaker but otherwise similar staining was obtained if the conjugate was applied to fixed and permeabilized cells. Treatment with 3.0 microM nocodazole induced depolymerization of MTs and rounding up of the cells. At the same time, the Golgi complex was disorganized with dispersion of its stacks of cisternae throughout the cytoplasm and atrophy of the trans Golgi network. The lysosomes gathered around the dispersed cisternal stacks and the endosomes became fewer in number. Moreover, the uptake of WGA-HRP was markedly inhibited. Following withdrawal of the drug, MTs reformed and the structural organization of the cell was again normalized. If the recovery was allowed to take place in the presence of low concentrations of nocodazole (0.03 or 0.15 microM), MTs of short and medium length were formed, the latter showing a curly path. In parallel, a partial or nearly complete normalization of cell morphology occurred. Internalization and transport of WGA-HRP labeled membrane to the lysosomes and the trans Golgi network was also resumed. In contrast, the cells were not able to pass through mitosis in a normal manner and multimicronucleated cells accumulated. Taken together, the findings indicate that L929 cells contain a subset of nocodazole-resistant MTs which play an important role in the structural organization of the cell, especially with regard to the Golgi complex and the lysosomal system. They support recent notions that there exists subpopulations of MTs with different physicochemical properties and functions.

Animals↗
PubMed1988

Comparison of bone formed intramuscularly after transplantation of scapular and calvarial osteoblasts.

Previous work suggested that osteoblasts determine the size of the bone marrow area within the bone and that calvarial osteoblasts differ from those induced intramuscularly by cartilage formed by transplanted epiphyseal chondrocytes. This study reports morphological observations of bone formed by transplanted scapular and calvarial osteoblasts isolated from bones of young rats. In intact scapulas of 28-day-old rats the percentage area occupied by bone tissue in relation to bone marrow was 6 times larger than in parietal bones of comparable age. Isolated syngeneic scapular osteoblasts usually produced an ossicle with similar general structure and ratio bone tissue/bone marrow area as in intact scapulas. In transplants of calvarial osteoblasts numerous islands of bone tissue with a small amount of bone marrow appeared. Bone formed in allogenic transplants was rejected. These results suggest that osteoblasts from endochondral scapular bone may have different properties than those from intramembranous calvarial bones. Alternatively, the large amount of medullary space in bone produced by transplanted scapular osteoblasts could result from their contamination with bone marrow stromal cells.

Animals↗
PubMed1988

Occurrence of large groups of mast cells in subcutaneous connective tissue in the mouse.

Skin from the mouse trunk together with panniculus adiposus and panniculus carnosus and, separately, trunk muscles, were fixed, stained with Astra blue at pH 1.0, made translucent in methyl salicylate and whole-mounted. In the connective tissue on the surface of panniculus carnosus directed towards the trunk muscles or on the surface of trunk muscles rounded and oval mast cells occurred singly or in groups from two to several dozen cells. These groups had no association with blood vessels or hair follicles. Mast cell groups were scarse in 1-month-old, clearly recognizable in 2-months-old and conspicuous in 4-months-old mice of both sexes. The number of mast cells and their number per group was larger in CFW/Ll and C3H than in Balb/c mice. Accumulation of mast cells in subcutaneous connective tissue was noted in animals from two separate breeding centers. The animals were free of ectoparasites and dermatophytes but contained some pinworms and protozoa. Elimination of these parasites, change of diet and drinking water as well as cage lining did not prevent the appearance of mast cell accumulations. These accumulations occurred in all studied mice (over 100) at the age of 2 months or older, and were also found in 1 out of 6 four-month-old hamsters and in 2 out of 6 four-month-old rats. It is suggested that mast cells accumulate in subcutaneous connective tissue in response to some undefined noxious agent. Whatever the reason of their presence, large groups of mast cells could considerably influence the results of tests performed in the skin-hypodermis area.

Animals↗
PubMed1988

Effect of immunosuppression on survival and growth of cartilage produced by transplanted allogeneic epiphyseal chondrocytes.

Strong short-term immunosuppression improved survival of cartilage formed by transplanted allogeneic epiphyseal chondrocytes in mice. The agents tested were cortisone acetate (CA), cyclophosphamide (CY), procarbazine (PCH), and antithymocyte serum (ATS). Their effect on syngeneic grafts was examined morphologically and histomorphometrically. In untreated recipients, chondrocytes formed cartilage nodules that underwent endochondral ossification. Except for high repetitive doses of CY, none of the other agents interfered with normal cartilage formation. However, all agents affected endochondral ossification. In the allogeneic system, the effect of immunosuppression was examined morphologically and by evaluation of specific humoral and cellular antigraft immunity. Allogeneic chondrocytes evoked a strong immune response in untreated mice, and cartilage was gradually destroyed by infiltrating cells. Endochondral ossification did not occur in this system. Neither agent given alone exerted a marked, long-lasting protective effect upon the graft. However, combined treatment with ATS and PCH inhibited immune response and completely prevented infiltrate formation and allowed endochondral ossification similar to that in the syngeneic control. Although some weak signs of antigraft immunity were seen after six weeks, it is possible that they were due to secondary exposure of antigen-bearing chondrocytes in the course of endochondral ossification.

Animals↗
PubMed1988

On the role of the nucleus in the structural organization of the cell: dispersion and rearrangement of the Golgi complex in cytoplasts treated with antimicrotubular drugs.

Using cytochemical and electron microscopic techniques, it was shown that enucleated L929 fibroblasts retained a radiating pattern of microtubules as well as a large and circumscribed Golgi complex for at least one day. At the same time, the number of ribosomes and the overall size of the rough endoplasmic reticulum were reduced, probably as a result of the arrest in production of new mRNA. Treatment of the cytoplasts with either of the microtubule-disruptive drugs colchicine or nocodazole led to loss of microtubules, aggregation of intermediate filaments in large bundles, and a characteristic disorganization of the Golgi complex with spreading of its constituent stacks of cisternae throughout the cytoplasm. After withdrawal of the drugs, microtubules reappeared, intermediate filament bundles disaggregated, and the Golgi complex resumed a morphology comparable to that of cells kept in normal medium during the entire experiment. In all these respects, the cytoplasts behaved in a similar way as nucleated cells. The observations confirm earlier notions of a role of the microtubular cytoskeleton in the organization of the Golgi complex. They further indicate that the information needed to support the normal structure and interaction of these organelle systems is present in the cytoplasm and does not require the physical presence of the nucleus, nor continuous nuclear activity, i.e. transcription and processing of mRNA.

Animals↗
PubMed1987

Influence of beta-D-xyloside on growth and histological aspect of long bones in chicken embryos.

It is known that beta-D-xylosides interfere with the proteoglycan synthesis in several tissues. A possible influence of this disturbed synthesis on the matrix formation of bone and cartilage has not been described light microscopically. In the present study we used 10-day-old chicken embryos which were exposed in ovo to a final concentration of 0.5 mM beta-D-xyloside. After 3, 6, 9, 20, 25, 31, 35 and 40 days, lengths of several skeletal elements were determined and the middle metatarsal bones were processed for light microscopical demonstration of acidic groups. The results demonstrate that beta-D-xyloside inhibits growth of long bones and induces synthesis of a cartilage matrix with a very low concentration of chondroitin sulphate. It has no noticeable influence on the amount of acidic groups in the organic bone matrix. Despite the absence of chondroitin sulphate, the cartilage matrix becomes mineralized normally.

Animals↗
PubMed1986

Structural differences between bone formed intramuscularly following the transplantation of isolated calvarial bone cells or chondrocytes.

Bone formed in intramuscular transplants of isolated syngeneic calvarial bone cells in mice, was compared with endochondral bone induced by cartilage produced by analogous transplants of isolated epiphyseal chondrocytes, as well as with parietal bones forming the bulk of the calvaria. Transplanted calvarial cells produced islands of bone, some of which contained intraosseous cavities. Osteoclasts inside these cavities were observed only in 14-day-old transplants and bone marrow cells in 28-day and older transplants. On the contrary, bone marrow appeared soon after formation of bone trabeculae in endochondral bone. The percentage area occupied by bone marrow in these specimens was about twentyfold larger than in the bone formed by transplanted bone cells. On the other hand, the bone marrow area in the latter type of bone was somewhat smaller but of similar order as in parietal bones. Moreover, both in parietal bones and in bone formed by isolated bone cells, the bone marrow was devoid of fat cells which were numerous in bone arising by endochondral ossification. It appears, therefore, that the ratio of bone marrow to the bone tissue area in parietal bones depends more on the intrinsic properties of osteoblasts than on the local factors in the environment of the developing bone. In the case of bone induced by cartilage, the bone marrow/bone tissue area could be determined both by the extent of cartilage resorption by vascularized tissue and by the properties of osteoblasts.

Animals↗