PubMed Health⌕ Search

Biomedical subjects

M Mára

Publications and source records attributed to M Mára.

At least 37 records · Page 2Linked to original sources
PubMed1995

Prolonged survival of AVN Wistar rats with transplanted Yoshida sarcoma and increase of granular lymphocytes after administration of Bacillus firmus and their crude lipids.

Bacillus firmus is a Gram-positive, aerobic, sporulating, nonpathogenic air contaminant which, according to earlier findings, is a strong polyclonal activator of B lymphocytes. The crude lipids of this microbe induced significant resistance of mice against listerial infection. The administration of bacterin, like that of crude lipids obtained by the extraction of cell suspension with chloroform-methanol to rats, strain AVN Wistar, transplanted later with Yoshida sarcoma, significantly prolonged the survival of the animals in comparison with the control group. At the same time the number of granular lymphocytes was increased. The destruction of tumor cells in the peritoneal exudate of immunostimulated rats was also determined.

Adjuvants, Immunologic↗
PubMed1995

Polyclonal activation of human lymphocytes by Bacillus firmus and its constituents.

Bacillus firmus strongly stimulates Ig synthesis in the cultures of human peripheral blood mononuclear leukocytes. As apparent from the character of Ig formation and blastic transformation, the stimulation has features of a polyclonal activation of B lymphocytes without substantial participation of T lymphocytes. B firmus is a strong B cell polyclonal activator even for human cord blood lymphocytes. The most striking feature is the strong stimulation of IgA synthesis in both adult and cord blood lymphocytes. Several crude fractions were isolated from B. firmus. None of them exhibited any remarkable enhancement of activity but the cytoplasmic fraction P-40 was clearly more potent than the intact bacilli. On the other hand, cell wall peptidoglycan, a well known polyclonal activator of B cells, had a much lower activity than whole bacteria. The effect of B. firmus on the stimulation of Ig formation is thus relatively complex; it is not caused mainly by peptidoglycan but rather by some cytoplasmic constituents of the bacterium.

Adult↗
PubMed1994

Effect of Bacillus firmus and other sporulating aerobic microorganisms on in vitro stimulation of human lymphocytes. A comparative study.

B. firmus activates human peripheral blood lymphocytes in vitro. Bacteria inactivated by heat or by formaldehyde were about equally effective, stimulating the blastic transformation of lymphocytes at doses of 10-200 mg/L and Ig formation in the culture at 10-500 mg/L. The action of formaldehyde treated B. firmus was compared with that of analogously inactivated B. subtilis, B. polymyxa, B. coagulans, B. megaterium, B. pumilus, B. cereus and B. lentus at a concentration of 100 mg/L. All these bacilli mildly stimulated blastic transformation and most of them substantially stimulated Ig formation, but B. firmus was the most efficient in stimulating the formation of Ig of all classes, in particular IgM and IgA. Its effect on Ig formation was comparable with that of PWM and was unusually high as compared with that of other bacteria. B. firmus is apparently a strong polyclonal activator of B lymphocytes. Its cells or their components could be potentially used for modulating immune reactions.

Bacillus↗
PubMed1994

Resistance to infection and activation of the monocyto-macrophage system caused by Bacillus firmus and its fractions.

Crude lipids isolated from Bacillus firmus, but not from other bacilli, were previously found to induce significant resistance against Listeria monocytogenes infection in mice. In this study, formaldehyde- and heat-killed bacterins of eight Bacillus species and some cellular fractions of B. firmus were prepared and tested for further immunomodulatory activities. Crude lipids, their aqueous extract, LTA, Protodyne and Pex-residue preparations exhibited a strong anti-infection activity, whereas Pextract, P40 and all bacterins tested had no effect. Formaldehyde-killed bacterins, live bacteria and the P40 preparation of both B. firmus strains, as well as bacterins of both B. subtilis strains, induced pronounced splenomegaly in mice. Peptidoglycan and Pex-residue induced significant depression of cytochrome P-450 in mouse liver microsomes after application of 0.1 mg per mouse. Optimal conditions for obtaining a bacterial suspension exhibiting these immunomodulatory properties were elaborated.

Adjuvants, Immunologic↗
PubMed1994

The influence of Propionibacterium acnes (Corynebacterium parvum) fractions on immune response in vivo.

Bacterin of Propionibacterium acnes (Corynebacterium parvum), its cellular fractions (lipids, fractions obtained by mechanical disruption and differential centrifugation, by phenol-water and pyridine extractions), and a polysaccharide from culture filtrate were prepared and tested in mice. The activation of RES by splenomegaly and hepatomegaly, prevention of listerial infection, prevention of the lethal effect of sarcoma 180, and depression of liver microsomal cytochrome P-450 were employed. The bacterin was effective in all tests. Lipid-free cells were less active, in particular in the activation of RES and in the listerial infection model. Fractions prepared by the disruption and differential centrifugation lost their activity in all tests along with a decrease in molecular weight. Lipids extracted by ethanol caused pronounced splenomegaly and decreased the cytochrome P-450 content. The residue left after the phenol-water extraction was very active, its delipidation did not destroy the activity. Pyridine extraction provided a completely inactive extract, but a very active residue. The possibility of reducing the complexity of bacterin while preserving immunomodulatory effect is demonstrated.

Adjuvants, Immunologic↗
PubMed1993

Experimental thyroiditis in guinea pigs and rabbits. Immunization with thyroglobulin and bovine thyroid gland suspension.

Morphological changes in the thyroid glands of the guinea pigs with autoimmune thyroiditis (EAT) experimentally induced by thyroglobulin (TGL) or immunization by the suspension of thyroid gland cells with CFA manifested mainly by atrophy and alterations of follicular cells, fibrotic tissue changes, formation of inflammatory lymphoplasmocytic infiltrations, multiplication of C-cells and by the increase in the proportion of lymphocytes with activated nucleoli in the tissue. The antigenic effects of TGL differed from those of the cell suspension; the effects of TGL participated especially in the formation of the infiltrates, the effects of cell suspension participated in the diapedesis of mononuclears and in the multiplication of C-cells. The findings correspond to the principal findings in human autoimmune lymphocytic thyroiditis. In an electron microscope, strongly dilated cisterns of endoplasmic reticulum (ER) and multiplied mitochondria in the cytoplasm of altered follicular cells were found. The wall of the follicles exhibited fully intact or altered C-cells. The latter had a large number of granules in cytoplasm with an unusually clear medullary substance. In the rabbit thyroid glands no morphological changes were observed following the immunization with both antigens. TGL antibodies examined immunohistochemically in the sera were present in all the sera of guinea pigs immunized with TGL and CFA. The antibodies determined by dot immunodetection were present in the sera of all guinea pigs immunized with TGL+CFA, the titres reached the level of 1:81 to 1:729; the highest titres were observed in the guinea pigs following the immunization by dose of 7.7 mg/kg after 12 weeks of immunization.

Animals↗
PubMed1992

Effect of crude bacterial lipids on the course of Listeria infection in mice.

Crude lipids from 37 strains belonging to 32 bacterial species were isolated. By injecting mice with lipids 5 d prior to challenge with a virulent strain of Listeria monocytogenes, immunostimulatory activity in 19 preparations was found. In general, lipids of Gram-negative bacteria appeared to be more effective. As to bacilli, an extraordinary activity was found in the lipids of Bacillus firmus. Lipids of various species of the genus Listeria were found to be active in approximately one-half of cases. Among other Gram-positive bacteria, significant activity of lipids was found in Corynebacterium xerosis, Propionibacterium acnes and BCG. The composition of fatty acids in the lipids did not differ significantly from that reported in the literature and their mutual differences could not explain the different biological activity. In selected strains of Gram-negative bacteria lipids were repeatedly purified with anhydrous chloroform; these preparations were found to be inactive as compared with original chloroform-methanol lipids.

Adjuvants, Immunologic↗
PubMed1991

Class IgG, IgM and IgA antibodies against Staphylococcus aureus antigens in human serum and saliva.

Using the ELISA method antibodies against the sonicate, teichoic acid (TA) and exoproducts of Staphylococcus aureus were determined in sera and saliva of healthy individuals. Main serum antibodies against all the antigens used were shown to be class IgG antibodies. However, antigens of the sonicate stimulated significantly even the systemic IgA response. In the saliva class IgA antibodies predominated, but IgG antibody levels against TA and exoproducts approached the level of IgA antibodies. Levels of IgM antibodies against all antigens tested were low in both the serum and saliva which corresponds with the anamnestic type of response. On the basis of these results one may assume that not only IgG, but also IgA antibodies are important in the systemic immunity against staphylococcal infection and in the immunity of mucous membranes; besides IgA, even class IgG antibodies play an important role.

Adolescent↗
PubMed1991

Immunostimulatory effect of Rothia dentocariosa in mice.

In mice killed Rothia dentocariosa cells in doses of about 1.5 mg dry weight activated anti-infection immunity to Listeria antigens and anti-tumour immunity to the ascitic form of mouse sarcoma S-180. Their probable target site is the macrophage. The Rothia-activated macrophages in human gingiva may take part in the pathogenesis of periodontal disease. Three models were employed to verify the immunostimulating properties of preventively administered Rothia dentocariosa bacterin-1) a spleen macrophage migration test, using mice immunized with Listeria innocua, with the soluble listeria Ei antigen as the antigenic signal, 2) determination of the increase in the Listeria monocytogenes LD50 for mice and 3) the prolongation of survival of mice carrying the S-180 tumour. In all three cases, the administration of Rothia bacterin stimulated the immune response to the later administration of other antigens. Furthermore, in the macrophage migration inhibition test, the chemotaxis of non-immune mouse macrophages was found to be stimulated. This gives evidence of the fact that Rothia bacterin has an activating effect on these macrophages.

Actinomycetaceae↗
PubMed1991

The role played the lipid fractions of Mycobacterium bovis BCG in the development of antituberculosis immunity in an animal experiment.

The authors investigated the antituberculosis and antitumour immunogenicity as well as tuberculin allergenicity of the lipid fractions from Mycobacterium bovis BCG strains of Danish, French, Japanese origin and of Czechoslovak 725. The fractions explored included phospholipids, Cord factor, ethanol-extractable lipids, waxes A, B, C + D and fats. The fractions were divided into three groups according to their effectiveness. 1. The Cord factor and phospholipids from all the studied strains were effective in the antituberculosis and antitumour models with the only exception of strain 725 phospholipids. Phospholipids from all strains were capable of inducing tuberculin allergy. 2. In the second group (waxes A, C + D and lipids extractable by ethanol) a variance was observed in the antigenic properties of identical fractions from different strains suggesting differing metabolism in the strains producing these fractions. A mixture of waxes C + D from the French and Danish strains showed a degree of suppression in its antituberculosis effectiveness. 3. Waxes B and fats were entirely ineffective in the antitumour model and, with the exception of waxes B from strain 725 and fats from the Japanese strain, in the antituberculosis model. The antituberculosis and antitumour effectiveness directly depended on the content of a mycolic acid complex in fractions. Tuberculin allergenicity was associated with the intensity of phospholipid production by mycobacteria.

Animals↗
PubMed1991

Insulin immunization of guinea-pigs: biochemical, immunohistochemical and morphometric findings with and without the use of adjuvant.

Changes in the blood glucose level, glucose (GTT) and insulin (ITT) tolerance tests, anti-insulin antibody production and morphological changes in pancreatic tissues (in particular the islets of Langerhans) were studied. After immunization by insulin (I) or insulin combined with an adjuvant (IE, IF), the blood glucose level rose, changes were observed in the GTT and ITT and after four successive immunizations the immunofluorescence technique also demonstrated anti-insulin antibodies. None of the above changes was observed in the controls, to which saline containing complete Freund adjuvant (SF) or Listeria factor (SE) was administered. On the other hand, the morphological picture changed in both the experimental (IE, IF) and control (SE, SF) groups, in which (round) cell infiltration of the fine connective tissue of the omentum and even of mesentery, with nonspecific granuloma formation was observed, while huge multinuclear cells appeared in the SF group. The changes were more frequent in the IE and IF groups. The volume density of the pancreatic endocrine tissue increased significantly only in the experimental groups (I, IE, IF), in which the increase was accompanied, to a varying degrees, by degranulation of the B-cells. The results of analysis of volume density changes of A-, B-, and D-cell populations were correlated with the blood glucose levels. The morphological findings may explain why the originally insignificant production of anti-insulin antibodies and the increase in the blood glucose level observed in guinea pigs after the repeated administration of chromatographically purified insulin are significantly enhanced by the administration of adjuvants together with the immunizing agent. Complete Freund adjuvant was found to be more effective than the Ei Listeria factor.

Adjuvants, Immunologic↗
PubMed1990

Effect of cytochrome P-450 inhibition and stimulation on intensity of polyethylene degradation in microsomal fraction of mouse and rat livers.

Polyethylene (PE) is degraded in microsomal fractions of mouse and rat livers with the formation of carbonyl groups. Infrared spectroscopy demonstrated formation of predominantly ketone groups and to a lesser degree ester and aldehyde groups. The inhibition and stimulation of cytochrome P-450 in mouse livers affected the formation of oxidative groups on PE. Phenobarbital doses of 3 x 0.05 mg per mouse increased the concentration of cytochrome P-450 and ketone groups on PE, whereas the vaccine Propionibacterium acnes (0.5 mg) and its pyridine fraction (0.5 and 1 mg) had the opposite effect. The coherence of cytochrome P-450 with oxidative changes on PE is compared and discussed with findings on implants in man.

Animals↗
PubMed1989

The immunological properties of listerial complex Ei.

Factor Ei, besides exerting toxic reactions, is amphipathic, antigenic, chemotaxinogenic, causes blastic transformation, adjuvant effect, hypersensitivity (MIF, skin test), activates the RES (splenomegaly), increases the macrophage production, prevents listerial infection in mice, mycobacterial infection in guinea pigs and enhances the effect of BCG experimental tuberculosis and neoplasia in mice (Sa 180).

Animals↗
PubMed1989

[The effect of Listeria factor Ei, BCG vaccine and a combination of both on the growth of experimental syngeneic tumors in inbred mice].

The investigation assessed, whether a nonspecific single and repeated immunization induced by Listeria monocytogenes Ei factor, BCG vaccine and their combination influences the growth of transplanted syngenic methylcholanthrene tumour depending on tumor graft cellularity. The cellularity of 10(4) and 10(5) were investigated. Tumour growth was examined 10 and 17 days after the inoculation. It has been found that single Ei factor administration did not influence the tumour growth. Single BCG vaccine favourably influenced the tumour growth, but in progressing time and cellularity the effect was failing. In combination of BCG vaccine and Listeria Ei factor the antitumour effect appeared to be most profound. In progressing time after the tumour grafting and graft cellularity the effect was disappearing. It was probably due to the fact that immunotherapy fails to control tumour mass with high cellularity. The antitumour effect potentiation by combination of BCG vaccine with Ei factor suggests a way to a possible combined antitumour immunotherapy.

Animals↗
PubMed1989

[An attempt to control the growth of syngeneic experimental tumors in inbred mice using Listeria factor Ei, BCG vaccine and a combination of both].

The investigation assessed, whether a nonspecific single and repeated immunization induced by Listeria monocytogenes Ei factor, BCG vaccine and their combination influences the growth of transplanted syngenic methylcholanthrene tumour depending on tumour graft cellularity. The cellularity of 10(4) and 10(5) were investigated. Tumour growth was examined 10 and 17 days after the inoculation. It has been found that single Ei factor administration did not influence the tumour growth. Single BCG vaccine favourably influenced the tumour growth, but in progressing time and cellularity the effect was failing. In combination of BCG vaccine and Listeria Ei factor the antitumour effect appeared to be most profound. In progressing time after the tumour grafting and graft cellularity the effect was disappearing. It was probably due to the fact that immunotherapy fails to control tumour mass with high cellularity. The antitumour effect potentiation by combination of BCG vaccine with Ei factor suggests a way to a possible combined antitumour immunotherapy.

Animals↗
PubMed1989

Biological and immunological properties of avirulent strain of Listeria innocua.

The strain isolated by Dr. J. H. Welshimer from plants has antigenic formula V (VI) IX; XV; XI; AB, C--serovar 6a, is non-haemolytic, produces lipase, and toxic factor Ei, is avirulent for adult mice, but causes encephalitis in sucklings. In organs of intravenously injected mice the strain persists and multiplies for 1-3 weeks. The protective effect against listerial infections in mice of this strain administered 2-14 days before challenge is dose depending. After 3 weeks induces resistance of guinea pigs to infection with Mycobacterium tuberculosis H37Rv measured by spleen weight and Feldman index. The hypersensitivity induced in animals is detectable by factor Ei and PPD or OT tuberculins using MIF method. A suspension of living cells of this strain injected intraperitoneally causes resistance to Mycobacterium kansasii in mice, measured by inhibition of loss of weight and decrease of the number of bacillus in their lungs.

Animals↗
PubMed1989

Experimental listeriosis in immunized sheep.

Sheep immunized with live or inactivated vaccine were challenged with a virulent strain of Listeria monocytogenes. Clinical manifestations, penetration of listeriae into the mucous membranes and persistence in organs were noted. Bacteriaemia caused by intravenous injection of high doses of virulent strain disappears in 3 days. Readily after inoculation, listeriae penetrate into the gastrointestinal tract where they persist for 8 days. Listeriae appear from the 3rd day in the conjunctiva and nasal mucous membranes with clinical symptoms of conjunctivitis and rhinitis whence they are eliminated in 8 to 14 days. The brain, liver and spleen of animals that died in 5 to 7 days were loaded with listeriae. Organs from immune animals sacrificed 14 days after challenge were negative by cultivation even when listeriomas were in the liver and spleen. Rapid penetration and persistence of listeriae are an expression of their increased affinity to epithelia of systems which are not only the portal of their entry but even the site of their secondary propagation and thus a source of infection.

Animals↗