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M Colić

Publications and source records attributed to M Colić.

At least 55 records · Page 3Linked to original sources
PubMed1992

Differential effect of cyclosporin application on epithelial cells of the rat thymus. Immunohistochemical study.

Young adult male Wistar rats were given 30 mg per kg of cyclosporin (CS) for 21 consecutive days. A panel of monoclonal antibodies was used to study the phenotype of thymic epithelial cells. After treatment with CS, subcapsular epithelial cells, although phenotypically similar to medullary epithelial cells, were changed in a similar manner to phenotypically distinct epithelial cells of the deep cortex. These cells became enlarged, stockier and their cytoplasmic prolongations were thicker and coarser compared with control cells and their number was not decreased. In contrast, the number of medullary epithelial cells was markedly reduced, whereby the cells with the most mature phenotype (CK8+10-19- and CK8+10+19-) were the most prominently depleted. No proliferation of thymic epithelial cells was detected as monitored by incorporation of 5-bromodeoxyuridine.

Animals↗
PubMed1992

Interferon gamma alters the phenotype of rat thymic epithelial cells in culture and increases interleukin-6 production.

Rat thymic epithelial cells (TEC) in long-term culture were characterized by anticytokeratin monoclonal antibodies (mAbs) and electron microscopy. Phenotypic analysis performed by a large panel of mAbs showed that the highest percentage of these cells was of the subcapsular/medullary type. Recombinant rat interferon (IFN)-gamma up-regulated class-I and class-II MHC expression by TEC in culture as confirmed by immunohistochemistry and flow cytometry, but did not significantly alter other cell markers. TEC supernatants of IFN-gamma-treated cultures showed higher interleukin-6 (IL-6) activity, compared to the control, as determined by proliferation of the IL-6-sensitive B9-cell line. Increased IL-6 activity was probably not a consequence of increased TEC number in IFN-gamma-treated cultures because IFN did not significantly stimulate TEC proliferation in vitro. In contrast, IL-6 significantly stimulated TEC proliferation, indicating that this cytokine is not only a regulatory molecule for T-cell proliferation, but could also be an autocrine growth factor for thymic epithelium.

Animals↗
PubMed1992

Phenotypic and ultrastructural characterization of an epithelial cell line established from rat thymic cultures.

An epithelial cell line (TE-R 2.5) was established from a long-term culture of rat thymic epithelium. Its epithelial nature was confirmed using anti-cytokeratin (CK) monoclonal antibodies (mAb) and electron-microscopy. TE-R 2.5 cells were reactive with K 8.13, K 8.12, CK 8, R-MC 18, R-MC 19 and Mar 3 mAb and bind Ulex europaeus agglutinin I. Based on the results of this study it was concluded that they possess the phenotype of subcapsular/perivascular or medullary epithelium. This was in accordance with Western blot analysis of water-insoluble cell extracts showing the presence of 56,000, 52,000, 50,000 and 48,000 MW CK polypeptides. In addition, TE-R 2.5 cell line coexpressed CK and vimentin (a 57,000 MW polypeptide) which was demonstrated using dual immunohistochemistry and Western blot analysis. Electron microscopy demonstrated that TE-R 2.5 cells have all the characteristics of hypertrophic thymic epithelial cells (TEC) localized in situ exclusively in the medulla and thus further characterized this line as a type of medullary TEC. Finally, TE-4F10 mAb raised against an antigen of TE-R 2.5 cells selectively stained a subset of medullary TEC in situ including Hassall's corpuscles indicating again the medullary origin of this TEC line.

Animals↗
PubMed1991

Cultivation, characterization and modulation of rat thymic non-lymphoid cells in vitro.

Thymic fragments of young adult rats were cultivated in vitro using an explant technique. Two weeks later, non-lymphoid cells were characterized by enzyme-cytochemistry and immuno-cytochemistry. Based on cytomorphological criteria and cell-specific markers approximately 95% of cells were classified into 3 main types: epithelial cells, macrophages and fibroblasts. The effect of dexamethasone and amphotericin B, known modulators of cell growth in culture was also studied. Quantitative analysis showed that amphotericin B inhibited proliferation of macrophages and epithelial cells, while dexamethasone suppressed proliferation of fibroblasts and promoted growth of epithelial cells.

Amphotericin B↗
PubMed1991

Expression and function of intercellular adhesion molecule 1 (ICAM-1) on rat thymic macrophages in culture.

The expression of intercellular adhesion molecule 1 (ICAM-1) was studied on freshly isolated rat thymic macrophages (TMF) and after their cultivation in serum-free medium using monoclonal antibody (mAb) 1A 29 and a streptavidin-biotin immunoperoxidase technique. ICAM-1 was expressed on about 80% of freshly isolated TMF. Upon cultivation, the percentage of ICAM-1+ TMF decreased to about 30-40% in 12-day-old culture. Using double immunofluorescence staining it was found that ICAM-1 was expressed both on cortical (R-MC 40+) and CMZ/medullary (R-MC 43+) macrophage subsets. ICAM-1 was up-regulated on TMF in culture by recombinant IFN-gamma, IL1 and TNF-alpha and was down-regulated by dexamethasone. Syngeneic thymocytes bound to cultivated TMF in a rosette form at both 37 degrees C and 4 degrees C. IFN-gamma treatment did not increase the binding formation. The binding between thymocytes and IFN-gamma-stimulated TMF at 37 degrees C was inhibited by pretreatment of TMF with anti-ICAM-1 mAb or pretreatment of thymocytes with anti-LFA-1 mAb, indicating that ICAM-1 on TMF is one of the ligands involved in TMF/thymocyte adhesion and subsequent direct cell-cell communication.

Animals↗
PubMed1991

Rat thymic epithelial cells in culture constitutively secrete IL-1 and IL-6.

To study the in vitro interactions between rat thymic non-lymphoid cells and thymocytes, we established a system for long-term cultivation of thymic epithelial cells (TEC). TEC were cultivated and successfully propagated for over 8 months in RPMI 1640 medium containing 15% FCS, dexamethasone, insulin, epidermal growth factor, and poly-L-lysin as an adhesive matrix. Their epithelial nature has been confirmed using monoclonal anti-cytokeratin (CK) antibodies. More than 95% of these cells were reactive with K 8.13 and CK 8 mAbs, which are pan-epithelial markers for rat TEC in situ. An epithelial cell clone (TE-R 2.5) established from a long-term TEC culture was 100% reactive with these anti-CK antibodies. Phenotypic analysis of TEC cultures was performed by a large panel of mAbs reactive with a subset of rat TEC or CK polypeptides as well as UIex europaeus agglutinin I using a streptavidin-biotin immunofluorescence assay. Although the results obtained demonstrated phenotypic heterogeneity among these cells, most cultures, including the TE-R 2.5 clone, were of subcapsular/medullary phenotype. Medium conditioned by TEC cultures exhibited IL-1 and IL-6 activities when tested on D10S and B9 sensitive cell lines, respectively. Cytokine activities were neutralized (IL-1) or significantly inhibited (IL-6) by specific polyclonal antibodies. In addition, both anti-IL-1 and anti-IL-6 antibodies reacted with TEC in culture and epithelial (CK-positive) cells on thymic cryostat sections, indicating that thymic epithelium provides an important intrathymic source for molecules contributing to T cell activation.

Animals↗
PubMed1991

Primary culture of rat thymic non-lymphoid cells: influence of culture time on the expression of macrophage differentiation antigens defined by monoclonal antibodies.

A panel monoclonal antibodies (mAbs) raised to rat thymic non-lymphoid cells has been shown to discriminate between distinct subpopulations of macrophages depending on their anatomic localization in the thymus. These reagents were used in this study to examine the expression of macrophage-associated antigens in primary culture of rat thymic stromal cells. The phenotype of both adherent macrophage (AM) monolayers and non-adherent cells (NAC) released in culture medium was studied at different time points after cultivation. More than 95% AM expressed ED1 and R-MC 38 antigens (pan-macrophage markers), class I MHC antigens (OX-18) and iC3b receptor recognized by OX-42 mAb. Most of them (70-85%) were reactive with ED2, R-MC 40, 41 and 42 mAbs specific for cortical and cortico-medullary zone (CMZ) macrophages. A much smaller percentage was positive with R-MC 43/44 and R-MC 46/47 mAbs staining CMZ/medullary macrophages and a subset of cortical macrophages, respectively. A minor subset of AM expressed class II MHC molecules which progressively decreased during cultivation. NAC were phenotypically heterogeneous. In comparison with adherent cells they contained a lower percentage of cortical/CMZ phenotype macrophages. In addition, NAC were slightly enriched in R-MC 43+ cells and more significantly expressed IA/E antigens (85-95%). ED3, R-MC 39 and 45 mAbs reactive with thymic macrophages in situ were mostly non-reactive with AM and NAC in culture.

Animals↗
PubMed1990

Interspecies differences in expression of cytokeratin polypeptides within thymic epithelium: a comparative immunohistochemical study.

Cytokeratin (CK) polypeptide expression within the thymic epithelium of several mammalian species (mouse, rat, calf, pig, rabbit, and human) has been analyzed by the streptavidin-biotin immunoperoxidase method. Comparative analysis by a large panel of 17 monoclonal antibodies (mAbs) specific for individual CK polypeptides, pairs, or groups showed considerable heterogeneity of thymic epithelial cells (TEC) in each species. In addition, extreme interspecies difference in CK contents was observed. Four main phenotypic zones: the subcapsule/perivascular area, cortex, medulla, and Hassall's corpuscles (HC) were clearly identified, each characterized by different CK expression. Medullary TEC were more heterogenous and shared common CK polypeptides either with subcapsular/perivascular TEC, cortical TEC, or HC, in most species.

Animals↗
PubMed1990

Ontogeny of rat thymic epithelium defined by monoclonal anticytokeratin antibodies.

Ontogenetic study on the expression of cytokeratin (CK) polypeptides within particular subsets of rat thymic epithelial cells (TEC) has been performed by a large panel of anti-CK monoclonal antibodies (mAbs) using the streptavidin-biotin immunoperoxidase method. Simultaneous presence of two or more CK subunits in the same TEC has been demonstrated by double immunofluorescence labeling. The obtained results showed that the expression of CK polypeptides in fetal and neonatal thymus differed from the adult patterns. The main difference was observed in expression of CK10, 18, and 19 polypeptides. During fetal ontogeny, CK10 and 18 are markers for most medullary TEC or a subset of medullary TEC, respectively, whereas CK19 is mainly a pan-TEC marker. In the adult animals, they are localized in the cortical and a subset of medullary TEC (CK18), subcapsular/perivascular and some medullary TEC (CK19), or in a subset of medullary TEC and Hasall's corpuscles (HC) (CK10). The switch in their expression in the cortex was observed during the first two weeks of postnatal life.

Animals↗
PubMed1990

Ultrastructural study of germinal center macrophages in peripheral lymphoid organs of the rat.

The ultrastructural study of macrophages of germinal centers in the secondary lymphoid follicles of the rat spleen and mesenteric lymph nodes was performed. It was demonstrated that besides macrophages containing necrotic lymphocytes and plasma cells in various stages of degradation (which are already well described in the literature) the germinal centers are also populated with macrophages displaying specific ultrastructural features which enable their precise identification. These cells contain numerous vacuolar inclusions of different size, filled with electron lucent, flocculent material. The dense bodies and membrane profiles are also present in varying amount within the vacuolar content. The dense bodies contain polysaccharides which are detected by the thiocarbohydrazide-silver proteinate method. Very rarely, these cells contain the phagocytosed cellular debris, which is readily distinguished from the cytoplasmic inclusions.

Animals↗
PubMed1990

Immunohistochemical characterization of rat thymic non-lymphoid cells. II. Macrophages and granulocytes defined by monoclonal antibodies.

A panel of monoclonal antibodies (mAb) raised to antigens of rat thymic non-lymphoid cells (predominantly macrophages and granulocytes) was immunohistochemically characterized. Based on their staining patterns on cryostat thymic sections and double labellings using acid phosphatase activity, anti-cytokeratin mAb to exclude binding to epithelium or ED1 and ED2 mAb, specific for rat macrophages, antibodies were subdivided into four groups: (i) R-MC 39 mAb strongly reactive with macrophages in the cortex and cortico-medullary zone (CMZ) and weakly with some scattered macrophages in the medulla, blood vessels and thymocytes; (ii) R-MC 40, 41 and 42 mAb specific for cortical macrophages and most CMZ macrophages; (iii) R-MC 43 and 44 mAb predominantly recognizing CMZ and medullary macrophages; (iv) R-MC 45 mAb strongly labelling granulocytes and weakly a subset of macrophages throughout the thymus and isolated cells in the medulla. The obtained results show considerable heterogeneity within mobile thymic non-lymphoid cells and the presence of specific or common antigens in macrophages of particular topographic localization in the rat thymus.

Animals↗
PubMed1989

Macrophages of the rat thymus after cyclosporin treatment. Histochemical, enzymehistochemical and immunohistochemical study.

Young adult Wistar rats received 40 mg/kg of cyclosporin perorally for 21 days. Cyclosporin induced almost total disappearance of thymic medulla, whereas the cortex remained preserved. Although the density of cortical macrophages did not change significantly, their characteristics altered markedly and they became enlarged and rounded. In addition to an increase in acid phosphatase and nonspecific esterase activities, cortical macrophages developed very strong succinic dehydrogenase and chloroacetate esterase activities and a fine, granular, aldehyde fuchsin-positive cytoplasmic content. However, these cytoplasmic granules were PAS-negative and were not sudanophilic. Cortical macrophages retained their normal antigenic properties (which were studied by the use of ED1, ED2 and R-MC 41 monoclonal antibodies). Phagocytic cells in the remaining medullary islands retained their usual characteristics. The changes in cortical macrophages after cyclosporin treatment are discussed, especially in relation to the characteristics of macrophages of the cortico-medullary zone in the normal rat thymus.

Acid Phosphatase↗
PubMed1989

Thymic response to thermal injury in mice: I. Alterations of thymocyte subsets studied by flow cytometry and immunohistochemistry.

The dynamics of thymocyte subset changes in mice subjected to sublethal thermal injury were studied in cell suspensions by flow cytometry and in situ by immunohistochemistry. Thermal injury caused acute thymic involution in the first 2 days which was the consequence of a considerable decrease in numbers of Thyl.2high+ CD4+ CD8+, cortical thymocytes. Medullary, Thyl.2low+ thymocytes were more resistant and their relative values increased. In the regenerative phase (2-14 days) the recovery of large CD4- CD8-, early thymocytes, mainly localized in the subcapsular area of the thymus, preceded the regeneration thymocytes of the cortical phenotype. Judged by the absolute numbers of medullary thymocytes it can be seen that CD4+ CD8- (T-helper/inducer cells) were more sensitive to the effect of thermal injury than CD4- CD8+ (T-suppressor/cytotoxic cells). While values of CD4+ CD8- cells were constantly and progressively lower during 2 weeks after thermal injury, absolute numbers of CD4- CD8+ cells showed cyclic changes with lower and higher values compared to controls. An increase in the numbers of CD4- CD8+ cells was found at day 6 after thermal injury.

Animals↗
PubMed1989

The effects of submandibularectomy on the thymus and the T cell system of mice. The morphological changes.

Morphological changes of the T cell immune system compartments (thymus and spleen) and the steroid hormone producing glands (adrenal and testis) in the submandibular-ectomized (SMx) male mice of CBA/H strain were analyzed. Thymus, spleen, testis and adrenal gland were weighed and processed for the morphological examination by light- and electron-microscopy. The serum level of testosterone was evaluated by radioimmunoassay. No weight and morphological changes were observed in the testis and adrenal gland, and the testosterone level in sera was not changed after SMx. These results indicate that any relationship between the submandibular salivary glands and the immune system was not mediated through them. The epithelial hormone-producing cells located in thymus medulla showed the most prominent changes after SMx evaluated by the neuron specific enolase immunostainings and by the ultrastructural analysis. After SMx, the number of very active epithelial hormone-producing cells in both cortex and medulla of the thymus was markedly increased.

Adrenal Glands↗
PubMed1989

Immunohistochemical identification of six cytokeratin-defined subsets of the rat thymic epithelial cells.

Rat thymic epithelial cells (TEC) have been studied by a panel of monoclonal antibodies specific for single cytokeratin polypeptides or cytokeratin pairs. Using various combinations of single and double immunostainings 6 TEC subsets (CK types) were identified, each characterized by different cytokeratin expression. Subcapsular/perivascular TEC (TEC-CK type 1) share cytokeratins 7, 8, 19 with a subset of medullary TEC, while cortical TEC were reactive with anti-CK 8 and anti-CK 18 mAbs only (TEC-CK type 2). Additional 4 subsets were identified in the medulla; TEC-CK type 3 (CK 8 + 18 + 19 +), TEC-CK type 4 (CK 8 + 10 + 18 + 19 +), TEC-CK Type 5 (CK 8 + 10 + 10 +) and TEC-CK type 6 positive only with CK 8 of all above cytokeratins. This study extends the concept of TEC heterogeneity and might also be useful to further understanding of TEC origin, development and functions.

Animals↗
PubMed1989

[Ethical aspects of plastic surgery].

In the past few years the abuse of ethical principles in plastic surgery has become increasingly noticeable. The reasons are various; it may be the desire to achieve personal recognition of plastic surgeons by means of different press articles or numerous yellow-press articles written by journalists whose only aim is to increase the circulation of their newspapers. In extreme cases the violation of medical secret or the surgeon's personality advertising is noticeable. Although this phenomenon is much more evident in the countries where plastic surgery is being performed at private clinics, it has in the past few years also become more obvious in our country. These ethical problems are present in plastic surgery because it is to often identified with aesthetic surgery. The fact that, with its more or less favorable results, it appears highly attractive to the public and thus get even the unwilling surgeon into the focus of various yellow-press articles and headlines. On the other hand, the very nature of the individual who specializes in this kind of surgery may be the principal basis for publicity. Such abuse of professional ethics is usually explained by claiming that the public should be properly informed, but in some cases it is but open advertising of the surgeon and his/her abilities. Establishing an ethical code which would entail all necessary moral sanctions in plastic surgery would act favorably to the protection of those plastic surgeons who perform their work according to the moral and ethical principles of their profession.

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