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Biomedical subjects

M Ferencík

Publications and source records attributed to M Ferencík.

At least 19 recordsLinked to original sources
PubMed2003

Modulatory effects of selenium and zinc on the immune system.

Almost all nutrients in the diet play a crucial role in maintaining an "optimal" immune response, and both insufficient and excessive intakes can have negative consequences on the immune status and susceptibility to a variety of pathogens. We summarize the evidence for the importance of two micronutrients, selenium and zinc, and describe the mechanisms through which they affect the immune status and other physiological functions. As a constituent of selenoproteins, selenium is needed for the proper functioning of neutrophils, macrophages, NK cells, T lymphocytes and some other immune mechanisms. Elevated selenium intake may be associated with reduced cancer risk and may alleviate other pathological conditions including oxidative stress and inflammation. Selenium appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Selenium deficiency has been linked to adverse mood states and some findings suggest that selenium deficiency may be a risk factor in cardiovascular diseases. Zinc is required as a catalytic, structural and regulatory ion for enzymes, proteins and transcription factors, and is thus a key trace element in many homeostatic mechanisms of the body, including immune responses. Low zinc ion bioavailability results in limited immunoresistance to infection in aging. Physiological supplementation of zinc for 1-2 months restores immune responses, reduces the incidence of infections and prolongs survival. However, in every single individual zinc supplementation of food should be adjusted to the particular zinc status in views of the great variability in habitat conditions, health status and dietary requirements.

Dietary Supplements↗
PubMed2002

Treatment of experimental adjuvant arthritis with the combination of methotrexate and lyophilized Enterococcus faecium enriched with organic selenium.

The efficacy of combination therapy with methotrexate (MTX) and probiotic bacteria Enterococcus faecium enriched with organic selenium (EFSe) in rats with adjuvant arthritis was determined. Rats with adjuvant arthritis were given MTX (0.3 mg/kg 2-times weekly, orally); lyophilized E. faecium enriched with Se (15 mg/kg, 5 d per week, orally); and a combination of MTX plus EFSe for a period of 50 d from the immunization. Levels of serum albumin, serum nitrite/nitrate concentrations, changes in hind paw swelling, arthrogram score, bone erosions, whole body bone mineral density (BMD) and bone mineral content (BMC) were assayed in the rats as variables of inflammation and destructive arthritis-associated changes. Treatment with MTX and with the combination MTX + EFSe significantly inhibited markers of both inflammation and arthritis. Significant differences in favor of combination therapy with MTX + EFSe as compared to MTX alone were seen in serum albumin concentration, hind paw swelling and arthrogram score. Reductions in radiographic scores were also more pronounced in the combination therapy group. Combination therapy, but not MTX alone, inhibited the reduction of BMD and BMC; treatment with lyophilized EFSe alone had no significant effect on adjuvant arthritis in rats. The potent therapeutic effect of low dosage MTX therapy in combination with lyophilized EFSe on adjuvant arthritis in rats was shown.

Animals↗
PubMed2001

Detection of drug-induced, superoxide-mediated cell damage and its prevention by antioxidants.

The mode of the cytotoxic activity of three benzo(c)fluorene derivatives was characterized. The observed morphological changes of lysosomes or variations of mitochondrial activity are assumed to be the consequence of cell protection against oxidative damage and/or the part of the damage process. To establish the relationship between the quantity of superoxide (O2*-) generated and the degree of damage resulting from O2*-, a simple system based on measurement of 3-(4-iodophenyl)-2-(4-nitrophenyl)-5-phenyltetrazolium chloride (INT) reductase activity in the presence of superoxide dismutase (SOD) was used. The functionality of the chosen battery of in vitro tests was proved using several known superoxide inducers: cyclosporin A (CsA) and benzo(a)pyrene (BP), as well as noninducers: citrinin (CT) and cycloheximide (CH). From the results followed that the cell growth tests are much better indices of toxicity than the other tests. The model system for the evaluation of the protective capacity of antioxidants against superoxide-induced cytotoxicity included simultaneous exposure of HeLa cells to cytotoxic drugs and to quercetin (Qe), an antioxidant of plant origin. The complete abolishment of the inhibition of cell proliferation and clonogenic survival was concluded to be due to the protective effect of the antioxidant. These observations correlated with the decrease of superoxide content as estimated by the INT-reductase assay in the presence of SOD using the same model system, as well as with the increase of intracellular SOD content and its activity.

Antioxidants↗
PubMed1999

[Successful modification of human intestinal microflora with oral administration of lactic acid bacteria].

Lactic acid bacteria in food can transiently colonize the intestine and exert health beneficial (probiotic) effects. These include: 1. Lactose digestion, improvement of diarrheal disorders (including traveller's diarrhea), prophylaxis of intestinal and urogenital infections--as a result of formation or reconstruction of a balanced indigenous microflora. 2. Inhibition of the mutagenicity of the intestinal contents and reduction of the incidence of intestinal tumours. 3. Immunomodulatory effects resulting in the improved host resistance. 4. Depression of the serum cholesterol level. The most of these effects were observed in a group of adult subjects administered daily by a lyophilized Enterococcus faecium M-74 in the form of waffles (Dr. Ebi) during nine weeks of a double blind placebo controlled clinical trial. The bacterium temporarily colonized the host intestine and its secretion in stool persisted for six weeks after the last dose. The mean activities of beta-D-glucuronidase in stools of subjects given waffles containing enterococci were reduced comparing to stools of placebo subjects. After six weeks of daily eating the waffles with enterococci, an increased production of superoxide and other reactive oxygen intermediates by peripheral neutrophils was observed. The increase corresponded in time with an elevated formation of IgG by peripheral blood mononuclear cells after polyclonal activation with mitogenes. Higher activities of myeloperoxidase and elastase in peripheral neutrophils were also ascertained during eating of waffles containing of E. faecium M-74. Hence, intake of E. faecium M-74 in the form of waffles may have an significant immunostimulatory effect on both phagocytosis performed by neutrophils and antibody production. (Tab. 6, Ref. 29.)

Administration, Oral↗
PubMed1998

[Vascular endothelium as a factor in information transfer between the cardiovascular and immune systems].

In health, the vascular endothelium forms a multifunctional interface between the circulating blood and various tissues and organs of the body. It constitutes a selectively permeable barrier for macromolecules, as well as a nonthrombogenic and nonadhesive container that actively maintains the fluidity of blood. It is a metabolically active endocrine organ, serving as the source of multiple factors and mediators that are critical for normal homeostasis. These include vasodilators (nitric oxide, prostacyclin, endothelium-derived hyperpolarizing factor), vasoconstrictors (endothelin-1, thromboxane A2, prostaglandin H2 and components of the renin angiotensin system), various pro- and antithrombotic factors (e.g. tissue factor, platelet activating factor--PAF, von Willebrand factor), fibrinolytic activators and inhibitors (e.g. tissue plasminogen activator, plasminogen activator inhibitor-1), potent arachidonate metabolites (prostanoids), leukocyte adhesion molecules (e.g. E-selectin, P-selectin, intercellular adhesion molecule-1--ICAM-1, vascular cell adhesion molecule-1--VCAM-1), and multiple cytokines with activities of growth stimulators and inhibitors, transforming growth factors, proinflammatory and antiinflammatory mediators, tumour necrosis factors and chemotactic factors (chemokines). Besides these essential activities controlling the cardiovascular system, the endothelial cells represent an important part of the immune system as well. They have a pivotal role in the initiation and development of defensive and damaging inflammatory responses. Therefore endothelium can be considered as being the central equipment for the mutual exchange of life important information between the cardiovascular and immune systems. This in turn is leading to rapid advances in understanding the pathogenesis of some of the most serious and most common diseases, including inflammation, atherosclerosis and hypertension. (Tab. 7, Ref. 89.)

Animals↗
PubMed1997

[Is the immune system our sixth sense? Relation between the immune and neuroendocrine systems].

There is an overwhelming evidence that cytokines, peptide hormones and neurotransmitters, as well as their receptors, are present in the brain, endocrine and immune systems. The structure and pattern of synthesis of these peptides by leukocytes appear similar to those synthesized in the neuroendocrine system, although some differences exist. Once secreted, these peptide hormones may function as endogenous regulators inside of the each system and also in bidirectional communication between the immune and neuroendocrine systems. Such communication suggest an immunoregulatory role for the brain and a sensory function for the immune system which may sense stimuli that are not recognized by the central and peripheral nervous systems (noncognitive stimuli). The plasma hormone concentrations contributed by lymphocytes usually do not reach the levels required when the pituitary gland is the source, but because immune cells are mobile, they have the potential to deposit the hormone locally at the target site. Several immunoregulatory cytokines, including IL-1, IL-2, IL-6, IFN-gama and TNF are produced not only in the immune system but in the neuroendocrine system as well. They have profound effects on neuroendocrine functions especially on hypothalamic pituitary axes. Neuroendocrine influences that modulate the immune function mainly include mental and physical stress. It can reduce the resistance of organism to infectious diseases and malignancies by compromising the immune system directly or indirectly. The brain is not an immunologically privileged site and therefore may become the target of immunologic attacks resulting in neuroimmunological diseases with an autoimmune component. The impact of psychological and psychosocial factors on the immune system is studied by psychoneuroimmunology whereas neuroendocrine immunology is generally interested in the interactions between the immune and neuroendocrine systems under physiological and pathological conditions. The recognition of the identity of ligands and receptors in the immune, nervous, and endocrine systems suggest a radically altered view of the immune systems impact on other tissues and organ systems, and vice versa. This will undoubtedly change our understanding of physiology, and consequently should profoundly impact the practice of medicine. (Tab. 5, Fig. 4, Ref. 85.)

Animals↗
PubMed1996

Immunomodulatory effect of some amphiphilic detergents on the human promyelocytic HL-60 cells.

The effect of two anionic (sodium dodecyl sulfate (SDS) and sodium laurate), two cationic (didodecyldimethylammonium bromide (DDAB) and [(1-methyldodecyl)-trimethylammonium bromide (2-ATDBr)] and a nonionic [(1-methyldodecyl)-dimethyl-amine N-oxide (2-ATDNO)] amphiphilic detergents on the metabolic activation of phagocytes derived from human promyelocytic leukemia cell line HL-60 was investigated. SDS in the concentrations of 10(-4) M significantly stimulated the INT-reduction and superoxide production by HL-60 cells which were preincubated with phorbol 12-myristate 13-acetate (PMA) for a macrophage-like differentiation. This effect was not significant in the case of cells differentiated along monocyte-like and granulocyte-like pathways. A similar influence was observed by sodium laurate, but this effect was significant (P < 0.01) by INT-reduction only. Concentrations higher than 5 x 10(-5) M DDAB, 2-ATDBr and 2-ATDNO inhibited INT-reduction and superoxide generation in HL-60 cells differentiated along all three ways. Our results indicated that differentiated HL-60 cells may be used for in vitro testing of immunotoxic effects on respiratory burst in phagocytes.

Detergents↗
PubMed1996

Endogenous control and modulation of inflammation.

Inflammation is the body's reaction to invasion by an infectious agent, antigen challenge or even just physical, chemical or traumatic damage. To avoid damage of the surrounding tissue, inflammatory responses must be well ordered and controlled. The development of inflammatory reactions is mainly controlled by vasoactive substances, cytokines, products of the plasma enzyme systems, bioactive lipids, and adhesive reactions between individual inflammatory cells or between them and molecules of extracellular matrix. The mediators of inflammation controlling different types of inflammatory reactions differ. This review briefly describes the role of proinflammatory and anti-inflammatory cytokines, including chemoattractant cytokines (chemokines), acute phase reactants, and the molecular mechanism of leucocyte emigration from the postcapillary venules.

Cell Movement↗
PubMed1995

Hypocholesterolemic and immunostimulatory effects of orally applied Enterococcus faecium M-74 in man.

Lyophilized Enterococcus faecium M-74 was administered to 12 adult subjects in a daily oral dose of 5 x 10(9) bacteria for six weeks. The bacterium temporarily colonized the host intestine and its excretion with stool persisted for five weeks after the last does. The mean levels of serum cholesterol and LDL showed a a biphasic effect--an elevation followed by a sharp decrease (on day 64 of investigation). The decrease corresponded in time with a significant increase in the ability to reduce iodonitrotetrazolium and superoxide production by peripheral neutrophils incubated with zymosan or phorbol myristate acetate, and also with an elevated production of IgG by peripheral blood mononuclear cells. Hence, intake of E. faecium may have a hypocholesterolemic and immunostimulatory effect. It was also demonstrated that E. faecium significantly reduced the average activity of beta-D-glucuronidase in stools.

Adjuvants, Immunologic↗
PubMed1995

[Molecular and cellular mechanisms in inflammatory reactions].

Inflammation is a complex stereotypical reaction of the body expressing the response to damage of its cells and/or vascularized tissues. It is the body's reaction to invasion by an infectious agent, antigen challenge or even just physical, chemical, or traumatic damage. The development of inflammatory reactions is controlled by a number of cellular and molecular components. Leukocytes (namely neutrophils and macrophages) belong to the key inflammatory cells. Their accumulation in inflamed tissue results from adhesive interactions between leukocytes and endothelial cells within the microcirculation. The nature and magnitude of the adhesive interactions that take place within postcapillary venules are determined by a variety of factors, of which the contribution of different adhesion molecules (selectins, integrins, members of immunoglobulin superfamily) to leukocyte rolling, adherence, and emigration in venules is discussed. The main purpose of inflammation seems to be to bring fluids, proteins and cells from the blood into the damaged tissues for the elimination of injuring agent and triggering the healing and repairing processes. This is under the control of inflammation mediators which include vasoactive substances, proinflammatory and antiinflammatory cytokines, chemokines, acute phase reactants, bioactive lipids (prostanoids, platelet activating factor--PAF) and products of the plasma enzyme systems (complement, the coagulation clothing, kinin and fibrinolytic pathways) which are shortly reviewed. Several neuroendocrine hormones, neuropeptides, neurotransmitters and mainly glucocorticoids also play an important role of endogenous regulators of any inflammatory process. (Tab. 4, Fig. 1, Ref. 52.).

Animals↗
PubMed1993

Amphiphilic detergents inhibit production of IgG and IgM by human peripheral blood mononuclear cells.

All types (cationic, anionic and non-ionic) amphiphilic detergents significantly inhibited the production of both IgG and IgM by human peripheral blood mononuclear cells after polyclonal activation in vitro. The most potent inhibitors were didodecyldimethylammonium bromide (DDAB) and (1-methyldodecyl)dimethylamine N-oxide (2-ATDNO). They were able to suppress effectively the immunoglobulin production in 10(-3)-10(-8) M concentrations. A medium inhibitory effect was observed with Slovapon, sodium dodecyl sulphate (SDS) and Triton X-100, while Slovanik showed an inhibition only in concentrations higher than 10(-2)%. These results suggest that amphiphilic detergents may be characterized as potential immunotoxic substances with very negative effects on the immunoglobulin production.

Detergents↗
PubMed1993

[The effect of Staphylococcus aureus vaccine on professional phagocytes in vitro and in vivo].

Effect of Staphylococcus aureus vaccine on metabolic and functional activities of polymorphonuclear leucocytes and guinea pig macrophages was observed. The tested vaccine following a short contact with human polymorphonuclear leucocytes isolated from peripheral blood inhibited candidacidal and phagocytic activities, whereas the phagocytic index stayed unchanged. The tested vaccine stimulated the INT-reductase activity and superoxide production, as well as extracellular liberation of lysosome enzymes from polymorphonuclear leucocytes. Application of the Staphylococcus aureus vaccine to guinea pigs 35, 30, 28, and 23 days prior to the acquirement of peritoneal macrophages, augmented, as compared to the control group, the amount of peritoneal macrophages and their phagocytic activity. Candidacidal and metabolic activities stayed unchanged. The results imply that the contact of phagocytic cells with the antigen, affects their biochemical and functional activities. Activities are dependent of the length of the period during which the antigen stimulation takes place, and of its quantity. Examination of phagocytes can be recommended for adjustment of both, vaccine doses and intervals between their individual applications. (Tab. 5, Ref. 19.).

Animals↗
PubMed1992

Functional and metabolic changes of guinea pig peritoneal macrophages induced by bacterial vaccines.

Phagocytic activity of peritoneal macrophages of guinea pigs injected subcutaneously with bacterial vaccines was found to be increased. The phagocytic index remained unchanged or was decreased. In addition, a decreased candidacidal activity was observed. Metabolic activation of macrophages, measured by the INT test, was inhibited in unstimulated cells while cells stimulated with zymosan or opsonized zymosan exhibited higher values of the INT test as compared with control animals. After injection of vaccines the number of peritoneal macrophages was increased, but the spleen mass decreased.

Animals↗
PubMed1991

The immunoadjuvant effect of soluble glucan derivatives in mice.

We examined the effect of soluble derivatives of yeast glucan on the humoral immune response of various strains of inbred mice after administration of different doses according to various schedules. Glucan was injected i.v. or s.c. in a single dose or repeatedly. The immune response was examined by determining the titres of serum hemagglutinins against sheep erythrocytes (SRBC-Ab). The immunoadjuvant effect of glucan derivatives depends on the inbred strain used, on the dose of glucan, mode and time of administration with respect to antigen injection. The results have shown that the stimulatory effect of glucan derivatives occurred already after a single injection, the optimum dose being 10-20 mg/kg. Intravenous injection was more efficient than the subcutaneous one. In some cases, a slight increase of the spleen mass was observed.

Adjuvants, Immunologic↗
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 effect of soluble glucan derivates on spleen colony-forming units in sublethally irradiated mice.

We examined the effects of 5 soluble derivatives of yeast glucan on the formation of exogenous (CFU-S) and endogenous (E-CFU) colony-forming units in the spleens of sublethally irradiated (60Co, 6.5-7.0 Gy) mice of two inbred strains. For the estimation of CFU-S, glucans were administered intravenously either to donors or recipients of spleen cells 24 h prior to irradiation or removal of the spleen. The number of CFU-S was increased when both the donors and recipients were treated with glucan; the highest increase was obtained with glucans S, P and K. All glucan preparations increased significantly also the number of E-CFU even when administered 90 min after irradiation. There exist differences in the response to the stimulatory effect of glucans among individual mouse strains. Thus, for example, the stimulatory effect of glucan KM on the E-CFU number was significantly more pronounced in strain A/Ph than in strain C57Bl/6.

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↗