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J Stulík

Publications and source records attributed to J Stulík.

49 records · Page 3Linked to original sources
PubMed1994

Two-dimensional electrophoretic study of normal colon mucosa and colorectal cancer.

Two-dimensional gel electrophoresis has been used to analyze polypeptide composition of specimens of human normal colon mucosa and colorectal carcinomas. Immobilized pH gradient in the first dimension improved the separation and enabled us to analyze proteins from whole tissue samples with high reproducibility. Polypeptides were separated within sigmoidal 3.5-10 pH gradient and range of mol. weight 15-200 KD. In global, protein patterns of normal and malignant tissue seemed to be close to each other. We attempted to combine two-dimensional electrophoretic separation with the immunoblotting technique using patient sera to identify possible tumor antigens. From a wealth of spots on silver stained protein maps of adjacent normal colon mucosa or tumor tissue, only few spots gave positive reaction. These spots might be classified into two groups: 1) common for normal colon mucosa and tumor, 2) specific for tumor tissue. The extent of patient's antibody reaction with antigens appeared to correspond to urinary neopterin level, an index of immune activation.

Adenocarcinoma↗
PubMed1993

Two-dimensional gel electrophoresis of four serum samples from patients with IgD myeloma.

Sera containing IgD paraprotein present problems in identifying patients with monoclonal gammopathies because only a small or even no spike may be present on standard serum protein electrophoresis. We have detected heavy chains of IgD monoclonal protein by means of high resolution two-dimensional gel electrophoresis. Besides clearly identifying delta heavy chains in maps of serum proteins, we also found size and charge heterogeneity of monoclonal immunoglobulins. The results demonstrate the usefulness of two-dimensional gel electrophoresis in the analysis of selected cases of immunoglobulin malignancies.

Aged↗
PubMed1992

Reactive oxygen metabolites in inflammation.

The functions of professional phagocytes depending on oxygen are briefly discussed. After appropriate stimulation, membrane-bound enzyme systems are activated--phospholipase C, protein-kinase C and NADPH-oxidase complex--and superoxide anion is produced. This process is called respiratory burst and is essential for killing of microorganisms but it may cause tissue damage and inflammation. The influence of superoxide anion on metabolism is reviewed. More attention is paid to modulating effects of superoxide anion in connection with the development inflammatory process.

Animals↗
PubMed1991

[Modulatory effect of glucans on the function of murine macrophages, NK-cells and lymphocytes].

The particulate glucan (G1), soluble glucan preparations (G2 to G5, and G7) isolated from Saccharomyces cerevisiae, and glucomanan prepared from culture fluid after cultivation of Candida utilis (G6) were tested for their immunomodulatory activity in vivo and in vitro. In tests in vivo three soluble glucans (G3, G4, and G7) injected s.c. to mice in the dose of 10 mg/kg increased the cytotoxic activity of peritoneal macrophages. The influence of glucans on natural killer cells was without significance. The lymphoproliferative reaction of spleen cells to polyclonal mitogens was inhibited by all the preparations used with the exception of soluble glucan G2. The mitogenic effect of the preparations, co-stimulatory tests and direct cytotoxicity to cells of cell lines used in cytotoxicity assays were assessed in vitro. The transformation index of glucans in the study was increased according to the glucan and dose tested. Inhibition of the lymphoproliferative reaction measured by the co-stimulatory test for optimal concentration of Concanavalin A occurred in a wide range of doses for the preparations G1 to G6. The preparation G7 increased the incorporation of 3HTdR under the same conditions. The use of a suboptimal concentration of Concanavalin A revealed co-stimulatory activity of all the preparations tested. Assessment of the cytotoxic activity of peritoneal macrophages and of the activity of natural killer cells induced in vitro was complicated by the direct cytotoxicity of particulate glucan and soluble glucan G5 (carboxymethylglucan) for target cells (YAC 1, and YAC 1 and K 562 resp.).

Adjuvants, Immunologic↗
PubMed1990

The production of oxygen metabolites and their possible regulatory role in the course of tularemia infection.

The changes of oxidative metabolism were studied in the course of a primary infection of mice with attenuated strain of Francisella tularensis. Metabolic stimulation of peritoneal cells is associated with a significant increase in spontaneous tetrazolium derivative reduction, the production of superoxide anion and hydrogen peroxide on day 5 after the immunization. The enhancement of superoxide dismutase precedes the increase in superoxide anion secretion. The splenic cells of immunized mice obtained on day 3 and in vitro pulsed by tularemic antigen secreted lymphokins(s) that could induce a metabolic stimulation. The treatment of resting splenic cells with hydrogen peroxide induces the secretion of interferon activity. The changes of oxidative metabolism that appear early after the infection seem to be related to a sequential activation of cells and probably have a regulatory role in the induction of immune defence against F. tularensis.

Animals↗
PubMed1990

The activation of macrophages in the immune response against the intracellular bacterial pathogen Francisella tularensis.

The activation of peritoneal macrophages in the course of primary infection of mice with attenuated strain of Francisella tularensis is associated with 2.5 fold increase in spontaneous INT reductase activity on day 5 after the immunization. The splenic cells of immunized mice pulsed in vitro by specific antigen secrete lymphokine that is able to induce an increase in spontaneous INT reductase activity of resident peritoneal cells. The production of spontaneous superoxide anion by peritoneal phagocytes reaches the highest level on day 5 after the immunization. It does not correlate with the results of cytotoxic or phagocytic activities at this time interval. An enhanced superoxide dismutase activity precedes an increase of superoxide anion secretion. The production of hydrogen peroxide is rising till day 7 and is related to the cytotoxic activity of peritoneal phagocytes. Concerning the testing of F. tularensis antigen as immunization agent, no changes of oxidative metabolism were detected. This might be in connection with the insufficient protection effect of killed F. tularensis vaccine. The production of reactive oxygen metabolites, probably under the control of superoxide dismutase, together with secreted lymphokines during the first days after the infection may play a regulatory role in the induction of immune response against intracellular pathogen F. tularensis.

Animals↗
PubMed1989

[Interleukin 2. Biochemical aspects of structure and function. Review].

During the last several years, the important progress has been achieved in studying activation and proliferation processes altogether with differentiation of mononuclear cells and regulatory course of immune response. In addition to molecular biology, also the biochemical characterization of interleukins, mainly Interleukin 2 (IL 2), is of a substantial import. IL 2 is actionning as an amplificator of T and B immune cellular reactions, and it influences the production of lymphokines, i.e., gamma interferon as well as participates in antitumorous immunity. IL 2 belongs to the range of products being secreted by T lymphocytes following the specific antigenic or polyclonal mitogenic simulation of cells. It can be classed as a growth factor of cells and regulatory factor of immune responsiveness. The human IL 2 was isolated as a protein with Mr 16 kD. On the basis of complementary DNA, the molecular weight has been determined for IL 2 as 15.4 kD. The IL 2-related human gen is localized on 4th chromosome and the product of the respective gen is a protein composed of 133 amino acids. This very protein undergoes glycosylation on the 3d position having alpha-helicoid conformation. The murine IL 2 occurs rather as a dimer composed of two protein chains with Mr 16-18 kD. Variable degrees of glycosylation involve the heterogeneity and pI differences in isolated forms of IL 2. Actions of IL2 are triggered by its interaction with specific receptor, which appears on the T cells no sooner as they are activated by the antigen or mitogen. Following the IL 2 with receptor interaction, the hydrolysis of phosphatidylinositolphosphate occurs intracellularly as well as activation of proteinkinase C and a track of other biochemical reactions non-elucidated till now, which lead up to the transcription regulation of genes and transfer of mitotic apparatus from G1 into S phase of cellular cycle and of division of cells.

Animals↗
PubMed1989

Multistep scheme for testing immunomodulatory substances.

The presented multistep program for testing immunomodulatory properties of biological response modifiers offers the possibility to evaluate multilaterally the modulatory potential of the tested preparations and to obtain basic data concerning their acute immunotoxicity. The scheme is divided into four stages: screening, optimalization, modelling, and analytical stage, each of which can be carried out separately on a relatively individual basis. This division considers the effect of the preparation on basic functions of the cells participating in the network of immunoregulation, the influence on the course of the immune response, modulation of the reactivity of the immune system affected by a 'non-immunological' phenomenon, as well as changes in protein repertoire produced by different systems of cells exposed to the tested preparation and/or the immunogenic signal. Detailed toxicological evaluation should be performed separately from immunopharmacological evaluation, keeping in mind differences in the application of the substances and the animal model involved. Incorporation of mathematical modelling and computer analysis of the results obtained by using the scheme may prove valuable in solving problems associated with potential modulation of the host immune system in clinically significant situations.

Adjuvants, Immunologic↗
PubMedDate not supplied

The analysis of S100A9 and S100A8 expression in matched sets of macroscopically normal colon mucosa and colorectal carcinoma: the S100A9 and S100A8 positive cells underlie and invade tumor mass.

The expression of calcium-binding protein S100A9 was investigated in 23 matched sets of colorectal carcinoma and normal colon mucosa using two-dimensional gel electrophoresis. We found that, from a group of 23 patients, the level of S100A9 protein, in comparison with matched normal colon mucosa, was significantly increased in malignant tissues of 16 patients (70%). Furthermore, an additional protein, identified by matrix-assisted laser desorption/ionization - mass spectrometry (MALDI-MS) as S100A8, exhibited an increased expression in the same specimens of malignant tissues as the S100A9 protein. The immunohistological analysis revealed the accumulation of S100A9 positive cells, macrophages and polymorphonuclear leukocytes along the invasive margin of colorectal carcinoma. The S100A8 protein was found to be produced in the same location. The possible participation of both proteins and, especially, its heterodimeric complex calprotectin in colorectal carcinoma regression could be taken into account.

Antigens, CD↗
PubMedDate not supplied

Modulation of signal transduction pathways and global protein composition of macrophages by ionizing radiation.

It is assumed that the exposure of cells to ionizing radiation modulates their signal transduction pathways, which then govern the early and late radiation-induced alterations in gene expression. In this study we tested the effects of low doses of X-irradiation on the cell signaling and global protein composition of an HL-60 human promyelocytic leukemia cell line differentiated along a macrophage-like cell pathway by 4beta-phorbol-12-myristate-13-acetate (PMA). Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by immunoblotting of anti-phosphotyrosine immunoprecipitates, we found radiation-induced changes in the level of phosphorylation of proteins with molecular masses of 45 and 48 kDa, but in the most intensively stained area, ranging from 54 to 60 kDa, no alterations were observed. When two-dimensional electrophoresis (2-DE) immunoblotting was applied, only proteins from this heavily stained region were visualized and in addition the evident differences in tyrosine phosphorylated protein patterns between nonirradiated and irradiated cells were found in this area. Furthermore, the immunostaining of extracellular signal-regulated kinase 2 (ERK2) which did not prove its tyrosine phosphorylation demonstrated the existence of several ERK2 charge isoforms showing differential expression after X-irradiation. Comparing the whole protein profiles we found after the simultaneous quantitation of 1000 matched spots two proteins whose expression was regulated in an opposite manner in nonirradiated and X-irradiated cells. The quantities of both spots showed increases or decreases by a factor of 2 or more between irradiated and nonirradiated samples and both these changes were statistically significant (P<0.05).

Electrophoresis, Gel, Two-Dimensional↗
PubMedDate not supplied

The different expression of proteins recognized by monoclonal anti-heat shock protein 70 (hsp70) antibody in human colonic diseases.

Analysis of the expression of hsp70 (70 kDa heat-shock proteins) in normal and pathological tissues might prove their potential diagnostic and prognostic values. In the present study, we combined high-resolution two-dimensional polyacrylamide gel electrophoresis with immunoblotting to study hsp70 expression in normal, preneoplastic and neoplastic colonic mucosa. By monoclonal anti-hsp70 antibody, recognizing both the constitutive and inducible forms of hsp70, we have detected six charge isoforms localized in the pH 5.1-5.3 range and in the molecular mass range of 68-69 kDa in normal colonic mucosa. Immunostaining of hsp70 in polypous and malignant tissues revealed qualitative as well as quantitative changes in the expression of more acidic isoforms of hsp70 in comparison with normal tissue. Furthermore, the different basic isoforms of hsp70 were detected in chronically inflamed colonic mucosa from patients suffering from ulcerative colitis (UC) or Crohn's disease (CD). Besides the standard hsp70 protein pattern, additional proteins with molecular masses of about 39, 40, 74 and 75 kDa were variably immunostained in normal and pathological specimens. These observations suggest that hsp70 expression may be closely linked to disease etiology and/or pathophysiology.

Adenoma↗