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J Pekárek

Publications and source records attributed to J Pekárek.

At least 19 recordsLinked to original sources
PubMed1997

Stimulation of hemopoietic colony formation from mouse marrow cells in vitro using human dialyzable leukocyte extracts-IMMODIN-SEVAC.

The influence of dialyzable extract from human leukocytes (DLE) on the in vitro growth of the granulocyte-macrophage colony-forming cell (GM-CFC) colonies from progenitors of mouse bone marrow cells was studied. DLE alone did not induce the colony growth but it modulated the number of colonies if administered together with a colony-stimulating factor (CSF). The costimulatory effect prevailed in a broad range of DLE dilution and the index of increase was enhanced with the lowering of the CSF concentration. The costimulatory augmentation of clonal proliferation of GM-CFC with DLE was further strengthened by addition of indomethacin, thus indicating an intervening role of prostaglandins in the modulatory influence of DLE.

Animals↗
PubMed1997

[Control of autoimmune processes by natural and other non-harmful methods].

At present an increase of some autoaggressive diseases can be observed. The commonly used treatment consists of the administration of some immunosuppressive drug of some hormonal preparations. This type of therapy is accompanied by some undesired side effects, as these drugs influence also some other cell systems besides the immunologically active cells. These drugs are also known to lower the resistance to some intercurrent infections. Due to these undesired side effects some naturally occurring factors are introduced into the therapy. These are e.g., TGF-beta, or some interleukins (IL-10 etc.). In our department and immunosuppressively acting substance was isolated from DHL which had the ability to inhibit the AA (adjuvant arthritis) in rats. In humans this SF (suppressive factor) stimulates the CD 8+ cells which are known to have suppressoric activity. This SF was successfully applied in some autoaggressive diseases, e.g., atopic eczema, multiple sclerosis, some polyradiculoenuritis, amyotropic lateral sclerosis etc. In this paper the results in the ALS patients are given. Amongst other possibilities of the therapy the application of antilymphocyte sera, monoclonal antibodies to some CD markers of lymphocytes and some methods of hyposensitizations of tolerance induction are mentioned. Further, an original method using antigen bound to isosoluble carrier is described. This administration of encephalitogen bound onto Sforon (polyacrylate spheres) sis not only inhibit the EAE manifestations but also enable the survival of guinea-pigs which had already manifested the clinical signs of EAE.

Adult↗
PubMed1996

The effect of DLE fractions on GM-progenitors of haematopoietic stem cells in vitro.

Dialysable leucocyte extract (DLE) prepared from buffy coats of human blood, potentiates the effect of Colony-stimulating factor (CSF) on the growth of granulocyte-macrophage colony forming cell (GM-CFC) colonies in vitro. This relative increase of the number of colonies is apparent when diluted CSF (present in lung conditioning medium) as a control, and DLE, in a wide range of concentrations are added to the culture of mouse bone marrow cells. Fractionation of DLE on Amicon membranes revealed that the activity resides in molecules of 0-5 kD. Molecules 5-10 kD have no potentiating effect. DLE and its fractions (0-5 kD, 0-1 kD), except fractions 0-500 D and 5-10 kD, when added undiluted i.e. at the initial concentration, exerted a suppressive effect: colonies are not formed despite the presence of CSF. In a pilot experiment, it was shown that DLE is able to stimulate colony-forming activity of earlier progenitors of erythroid cells (BFUe), under the influence of erythropoietin.

Animals↗
PubMed1994

Influence of various forms of dialyzable leukocyte extracts on rat adjuvant arthritis.

Adjuvant-induced arthritis in rats is a chronic inflammatory disease, widely used as an animal model for rheumatoid arthritis. In our study the effect of various fractions of dialyzable leukocyte extract (DLE): DLE I-molecular weight below 10 kDa (commercial preparation), DLE II-molecular weight below 5 kDa (suppressor fraction), DLE III-molecular weight 5-10 kDa on rat adjuvant-induced arthritis was studied. The adjuvant arthritic (AA) rats were treated with DLE fractions i.p. in solutions containing an active substance isolated from 12.5 x 10(6) and 6.25 x 10(6) leukocytes from day 1 (adjuvant injected) through day 18, every second day (total 9 times). Various markers of inflammation, immune function and joint destruction were evaluated: hindpaw volume, serum hyaluronic acid, serum albumin and biopterin in urine. All these markers showed a significant improvement after using fraction DLE II in comparison with AA controls. Fractions DLE I and DLE III influenced only some markers of inflammation and immune function. Our results demonstrated a therapeutical effect of fraction DLE II on rat adjuvant-induced arthritis.

Animals↗
PubMed1991

[Low-molecular transfer factor and its use in the treatment of amyotrophic lateral sclerosis].

A low-molecular leukocyte dialysate, suppressor transfer factor (STF), exerting a stimulating effect on CD8 subpopulations in man, was administered to 17 patients with amyotrophic lateral sclerosis (ALS). Following three s.c. injections of STF, activation of CD8 subpopulations was noted in 11 patients while a decrease in CD4 in seven. Progression of the disease was found to slow in nine outpatients administered STF injections at an interval of 3-4 weeks. No therapeutic effect was seen in four patients in whom STF injection failed to show stimulating activity on lymphocyte subpopulations. Remission of the stimulating effect of STF occurs within four weeks. No side effects were seen in any of the patients treated. The effect of STF on immune reactivity and on the clinical course of ALS supports the hypothesis of autoimmune character of the disease.

Adult↗
PubMed1989

Course of liver regeneration after partial hepatectomy in rats treated with dialysates obtained 17 hours after partial hepatectomy.

Various theories have been put forward to explain the regenerative capacity of liver tissue induce by partial hepatectomy (PH). One of them presumes the existence of humoral factors stimulating proliferation of the liver tissue. We evaluated the course of liver regeneration after 65-70% PH as influenced by dialysates (DIA) of the organs of a rat killed 17 h after PH. In addition to kidney DIA, we were particularly interested in the effect of liver and spleen DIA. The experiments were carried out on rats weighting 310-370 g. Kidney, liver or spleen dialysate was administered subcutaneously and the rats were killed 12 or 24 h later by exsanguination from the abdominal aorta. In further rats, PH was performed 24 h after administering DIA and the rat were killed 18, 24, 30, 48 and 72 h after the operation. The initiation of liver regeneration was stimulated by all the given DIA, but especially by liver DIA. The faster onset of liver regeneration 18 h after PH in rats given spleen DIA is interesting. DIA did not greatly affect the hepatocytes of intact liver, but accelerated the initiation of liver regeneration after PH by synchronizing the cell cycle of proliferating hepatocytes. DIA obtained 17 h after PH contained substances which primarily stimulated liver DNA synthesis. From the changes in inhibition of the migration of spleen macrophages in the medium containing liver antigens, and from the circulating immunocomplex values, we conclude that DIA activation of the immune system, a well as the hepatic stimulator substance contained in the DIA, participates in acceleration of the liver regeneration process.

Animals↗
PubMed1989

Course of liver regeneration after partial hepatectomy in rats treated with dialysates of intact organs.

A number of growth phenomena observed in vitro have shown that cells, at high densities, produce and release substances which, when they have reached a given concentration, arrest further growth. In vivo, these possibilities can be studied on the model of rapid regeneration of the rat liver after 65-70% partial hepatectomy (PH). We evaluated the course of liver regeneration after PH in animals treated with dialysates (DIA) of intact rat tissues. In addition to kidney and lymph node DIA, we were particularly interested in the effect of liver and spleen DIA. The experiments were carried out on male rats weighing 210-240 g. The relevant DIA was administered 24 h prior to PH; the controls were given physiological saline. The animals were killed just before PH and 24, 48, 30 and 72 h and 14 days after. DIA obtained from intact liver tissue inhibited the regeneration process induced by PH and its effect persisted 48 h after PH. Compared with the controls and with the rats given kidney DIA, DNA synthesis in the liver 24 h after PH was reduced to 77%. After spleen DIA, several (still hypothetical) factors probably acted together synergically (factors belonging to the immune system--RES--and spleen-produced factors capable of promoting proliferation of the hepatocytes--the "portal blood factor"). We arrived at this conclusion from an evaluation of liver DNA synthesis 24 h after 24h after PH, when synthesis was altogether markedly raised, but attained far higher values after the administration of spleen DIA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Scintigraphic diagnosis of abscesses and other inflammatory processes using indium 111In labeled leukocytes].

Autologous polymorphonuclear leucocytes are injected after separation and labelling with 111In oxine to the patient with a suspect inflammatory process and after 24 hours their localization is assessed by standard scintigraphic examination by a scintillation camera. The authors examined in a prospective investigation 33 patients--the sensitivity of the method was in that group 80%, the specificity 100%, the diagnostic accuracy 94%. The authors discuss the possibilities of application of the method in intraperitoneal abscesses and in some inflammations with another localization. They evaluate the contribution of the method in the diagnosis of inflammatory processes, as compared with the possibilities offered by computed tomography and ultrasound.

Abscess↗
PubMed1988

Immunodiabetes in rabbits.

The changes of basal glycemia and of that during the glucose and insulin tolerance tests as well as of the production of hemagglutinating antibodies in rabbits immunized with crystalline insulin (CI), chromatographically purified insulin (CPI) and waste products of the chromatographic purification of insulin (WP), both with and without complete Freund's adjuvant (CFA) were studied. Following immunization with CI and its components the glycemia increased characteristically and the course of glucose and insulin tolerance tests was changed. The peak levels of antibodies were found following immunization with WP, while the lowest ones appeared following the application of CPI. Following the immunization with a mixture of antigens with CFA higher levels of antibodies were usually observed than following the administration of antigens without adjuvant. No association was found between the titers of antibodies and glycemia values. The principal morphological change in immunized animals was found to be a partial degranulation of B-cells, often accompanied by hyperplasia of A-cells. In groups immunized with CI or CPI mixed with CFA we detected even insulitis, which was absent in the other groups. Following immunization with CI mixed with CFA such cells were found whose granules in the ultrastructure showed conspicuous similarity to those of foetal (immature) rabbit B-cells. It was assumed that in insulin immunized rabbits the initial damage of islets was followed, at least in some regions, by reparative processes. This was indicated by the findings of mitosis figures in B-cells as well as by the islet A-cell hyperplasia.

Animals↗
PubMed1986

The patterns of complex and partially purified mycobacterial antigens in macrophage migration inhibition testing.

In rabbits immunized intratarsally by M. tuberculosis, M. kansasii and M. avium the responses to homologous and heterologous antigens were assessed by direct and indirect macrophage migration inhibition tests. Complex cytoplasmic antigens were obtained by disruption of bacterial mass and by ultracentrifugation of the supernatants. The partially purified antigens were prepared by gel chromatography of the complex antigens on a Sephadex G 150 column. The middle fraction (260/280 ratio approx. 1, molecular weight approx. 32 KD) was employed as partially purified antigen. In the direct tests the migration activity of immune spleen macrophages was significantly reduced by homologous complex and partially purified antigens (MI = 0.63 to 0.72) and it differed significantly from responses obtained with heterologous antigens (MI = 0.75 to 0.92); however, these were still lower than those in nonimmunized control animals where MI ranged from 0.89 to 1.01. In the indirect tests, the strongest responses were recorded again with homologous complex and partially purified antigens (MI = 0.43 to 0.53). The responses in heterologous systems differed even more markedly than in direct tests (MI = 0.65 to 0.81); and, these were again still significantly lower than in control animals (MI = 0.89 to 0.98). In both direct and indirect tests, the complex and partially purified antigens did not vary substantially in their immunogenic capacity. The presence of cross-reacting responses in heterologous systems can be explained by a close relatedness of mycobacteria used in the immunization schedule and by the presence of common epitopes in complex and purified testing antigens.

Animals↗
PubMed1985

Biological activity of synthetic subunits of streptococcus peptidoglycan. III. Relationship of subunit and analogue structure to adjuvant activity in cell-mediated immunity.

Each of a series of synthetic peptidoglycan subunits and subunit analogues was injected in combination with streptococcus type M24 antigen extract. The substances tested were: (8a) N-acetylmuramyldipeptide (MDP) and the following derivatives thereof: MDP modified in positions C3 and C4, or with L-alanine substituted by L-2-aminobutyric acid or with the peptide chain prolonged (by three lysines or a polylysine); (b) some synthetically prepared peptides: a hexapeptide, a tridecapeptide and an octadecapeptide. Configurations in positions C3 and C4 were found essential for the adjuvant effect. Adjuvant activity, though somewhat lower than in MDP, was pronounced in the analogue containing the L-2-aminobutyryl residue. Surprisingly, potent adjuvant effect was displayed by the hexapeptide; prolongation of the peptidic chain was not effective. The use of a polymeric carrier for MDP increased the adjuvant effect. Contrary to expectation, streptococcal antigens used with immunoadjuvant materials showed that induced delayed hypersensitivity was type related.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1984

Clinical and immunological characterization of systemic lupus erythematosus in patients with circulating interferon and migration inhibitory factor.

The simultaneous occurrence of interferon and migration inhibitory factor was found in sera from 9 patients with systemic lupus erythematosus (SLE). Their clinical picture was characterized by a moderate course of the disease. In 7 patients the inflammatory tendoarticular manifestations were accentuated. Glomerulonephritis was found only in 3 patients and was successfully suppressed by immunosuppressive therapy. In the peripheral blood of most of these patients, normal or moderately increased levels of active E-rosettes were found. Therefore we consider these SLE patients as a group with characteristic signs of activated cell-mediated immunity (lymphokine release, active E-rosettes). Although the reason for this activation remains unknown, we suppose that some concomitant bacterial infection, perhaps mycobacterial, may contribute to this immunological phenomenon.

Adult↗
PubMed1984

Effect of bilirubin on an in vitro correlate of cell-mediated immunity--the migration inhibition test.

The effect of bilirubin on one of the basic cell-mediated immunity reactions, i.e. the migration inhibition test was assessed. For this purpose the model of tuberculin hypersensitivity in rabbits was employed and the effect of bilirubin was studied on the migration inhibition test and its two main phases; the process of MIF production and the effect of already preformed MIF on the effector system. It was found that the neutralizing effect of bilirubin on the migration inhibition (caused by specific antigen) was due to the effect of bilirubin on the process of MIF production.

Animals↗