Magnetization and ferromagnetic resonance in a Fe/Gd multilayer: experiment and modelling.

Static and dynamic magnetic properties of a [Fe(35 Å)/Gd(50 Å)]12 superlattice are investigated experimentally in the temperature range 5-295 K using SQUID magnetometery and the ferromagnetic resonance (FMR) technique at frequencies 7-38 GHz. The obtained magnetization curves and FMR spectra are analysed theoretically using numerical simulation on the basis of the effective field model. At every given temperature, both static and resonance experimental data can be approximated well within the proposed model. However, a considerable temperature dependence of the effective field parameter in gadolinium layers has to be taken into account to achieve reasonable agreement with the experimental data in the entire temperature range studied. To describe the peculiarities of experimental FMR spectra, a non-local diffusion-type absorption term in Landau-Lifshitz equations is considered in addition to the Gilbert damping term. Possible reasons for the observed effects are discussed.

Effects of female sex hormones on adhesion of Candida albicans yeast-like fungi to the buccal epithelium.

Hormonal regulation of receptor expression and glycogen concentrations in the epithelial cells of the oral cavity remains poorly studied. Adhesion of microorganisms to the vaginal epithelium correlates with their adhesion to the buccal epithelium. Analysis of the correlation between Candida adhesion to the vaginal and buccal epithelium depending on the hormonal status has demonstrated that activity of Candida albicans strains in the buccal epithelium correlates with their adhesion activity in the vaginal epithelium, with the coefficient of correlations (r) reaching 0.76.

Effects of specific antibodies and immunocompetent cells on tumor growth in passive transfer experiment.

Experiments with passive transfer of immunocompetent cell and serum demonstrated suppression of tumor growth after transfer of splenocytes from animals immunized with Trypanosoma cruzi. The nonspecific constituent of antitumor effect of immunocompetent cells was detected. The previously reported oncoprotective effect of mucins 2 and 3 was not confirmed.

Effect of basal hormone profile on the formation of the vaginal bacterial cenosis in women.

Adhesion activity of L. acidophilus NK1, L. fermentum 90 TS4, and C. albicans 506 B on female vaginal epithelium was studied. Adhesion of various lactobacillus species was hormone-dependent. Adhesion of C. albicans 506 B was not associated with estrogen level. The effects of synthetic drugs and phytopreparations used for hormone replacement on adhesion of vaginal microbiocenosis members varied.

Phytoestrogen effects on vaginal microbiocenosis of Sprague-Dawley rats.

Phytoestrogens present in the plants endemic for Chile were studied. The effects of phytoextract [specimen of preparation No. 181 (fraction b)] on target tissues were similar to those of estradiol. The preparation inhibited the stimulatory effect of estradiol on vaginal lactobacilli population.

Modulatory effect of the lectin-binding component, added to gel, on adhesion of yeast-like Candida fungi in vivo.

The lectin-binding component added to gel was studied in vivo as a potential therapeutic and preventive agent in experimental vaginal candidiasis. Laboratory studies demonstrated its antimycotic effect in relapsing vaginal candidiasis in mice.

Damaging effects of lyticase on Candida albicans and changes in the response of rat alveolar macrophages to the contact with yeast-like fungi.

Changes in the cell wall of yeast-like fungi Candida albicans caused by bacterial enzyme lyticase were studied under an electron microscope. The results were compared with the findings on phagocytosis of lyticase-treated Candida albicans by rat alveolar macrophages. It was shown that destruction of the mannan and fibrous outer layers of the cell wall of yeast-like fungi treated with the enzyme led to the release of intracellular organelles and their content. Lyticase treatment reduced the resistance of Candida albicans to intracellular digestion by macrophages contributing to completion of phagocytosis.

Efficiency of lyticase (bacterial enzyme) in experimental candidal vaginitis in mice.

Lyticase (a bacterial enzyme) was tested as a new antimycotic drug. Of all objects studied, Cellulomonas cellulans AC-870 strain proved to be most productive for this enzyme. A technology for lyticase isolation and purification was proposed. An experimental model of recurrent vaginal candidiasis was created. The model includes combined antibiotic and estradiol therapy. Antimycotic effect of lyticase on the model of recurrent vaginal candidiasis in mice was demonstrated.

Study of antimycotic activity of lyticase.

Laboratory studies of lyticase (enzymatic drug) as an antimycotic agent were carried out. The enzyme reduced optical density of Candida albicans test culture, inhibited adhesion of yeast-like fungi on vaginal epitheliocytes, stimulated the formation of germinative tubes, and made Candida albicans more available for phagocytosis.

Fine-tuning of the spin-density-wave state in Cr/V heterostructures via hydrogen uptake.

We show that the magnetic state in rather thick Cr films can be finely tuned via hydrogen uptake into adjacent vanadium layers at rather low hydrogen pressures. By changing the hydrogen concentration and, hence, the electronic structure in the V layers, it is possible to affect the global properties of spin-density waves (SDWs) in Cr layers, including the SDW period and the Néel temperature. We provide direct experimental evidence that hydrogen uptake into V layers can be used to switch between incommensurate and commensurate SDW states in a reproducible way.

The study of immunological component in antitumor effect of Trypanosoma cruzi.

The experiments with passive transfer of splenocytes obtained from animals immunized with Trypanosoma cruzi lysate revealed the role of cell-mediated component of the immunity in the antitumor effect of T. cruzi. The common features of T. cruzi antigens and tumor-specific antigens of Ehrlich's adenocarcinoma were demonstrated. These antigens were shown to have common epitopes with mammalian mucins. The oncoprotective effect was achieved by immunization with type II and III mucins and was reproduced after passive transfer of splenocytes from immunized animals.

Adhesion characteristics of lactobacillus is a criterion of the probiotic choice.

A sampling of lactobacilli from the German National Collection of Microorganisms and L. fermentum 90 TS-4 (21) reference strain clone 3 (Russian Federation) were studied. The results indicate that the receptors on the surface of lactobacillus strains from the German collection had no structures complementary to type 1 fimbriae, though adhesins of some of them reacted with mannose and galactose receptors. Adhesion on a monolayer of continuous cell cultures showed that adhesion activity of lactobacilli was a function of many derivatives, and hence, the choice of a model for evaluation of the adhesion characteristics of the strain should be based on adhesins exhibiting universal properties in different test systems. One of them can be lectin-binding adhesin; its expression on the surface of cultures of lactobacilli from the German collection varies within the same range as was shown previously for lactobacilli, studied by the same criterion. The molecular weight of lectin-binding adhesin is 25-30 kDa, and the corresponding receptors are frequently present on various eukaryotic cells, and hence, cell models can be considered as the most adequate for studies of the competitive interactions between lactobacilli and adhesins of pathogenic microorganisms.

[Antibodies against Trypanosoma cruzi in intact mice and their oncoprotective effect].

Trypanosoma cruzi antibodies that are important in the anticancer effect of this species of Trypanosoma were first detected in 14% of the 374 examined intact mice. These background antibodies were polyclonal, i.e. they reacted with one or other of 9 genetically different T. cruzi clones and detected antigenic determinants in different structures of a Trypanosoma cell. Their spread in the population varied with animal batches; the titers were not greater than 1:40 and the level remained steady during a one-month observation. The growth of Ehrlich's adenomacarcinoma inoculated to these mice was inhibited by 1.5-2.5 times and, in some cases, terminated in total regression. The paper discusses the capacities of such antibodies in man and their inductor-commonness of the antigens of the normal intestinal microflora and the cells of the vertebrate with T. cruzi.

Bactericidal activity of culture fluid components of Lactobacillus fermentum strain 90 TS-4 (21) clone 3, and their capacity to modulate adhesion of Candida albicans yeast-like fungi to vaginal epithelial cells.

Antagonistic activities of L. fermentum strain 90 TS-4 (21), L. casei ATCC 27216, and L. acidophilus ATCC 4356 and bactericidal activity of lactobacillus culture fluid towards E. coli strain K12, S. aureus, and S. epidermidis test cultures were studied. The bactericidal effect of L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation (pH 6.0) on the test cultures was dose-dependent. Adhesion of C. albicans yeast-like fungi to vaginal epitheliocytes was more pronounced for strains isolated from women with asymptomatic infection than for strains isolated from women with manifest forms. L. fermentum strain 90 TS-4 (21) clone 3 culture fluid preparation modulated adhesion of yeast-like fungi only if the fungal strain was initially highly adherent.

Study of antibody production to Tamm-Horsfall protein in renal transplant donors and recipients.

The content of Tamm-Horsfall protein was measured in the urine of humans without renal diseases, pregnant women, and donors and recipients of renal transplant using a new test system for measuring Tamm-Horsfall protein including antigenic diagnostic agent and immune serum. Production of antibodies to Tamm-Horsfall protein was characterized using antigen diagnostic system.

Characterization of surface adhesins of lactobacilli used in production of probiotic preparations.

We examined production of the protein-lipoteichoic complex detectable by concanavalin A in six lactobacillus strains. A correlation was found between detection of this complex by both reaction with concanavalin A and agglutination with strain-specific antiserum. The cultures were characterized by expression of different types of adhesins. Among them, strains were differentiated with low adhesion activity and intensive production of the protein-lipoteichoic complex and strains with wide adhesin spectrum not producing the complex. We assume that a combination of lactobacillus variants differing in production of the protein-lipoteichoic complex and adhesion potency can be a basis of efficient probiotic preparation.

In vivo anticancer activity of lysates from trypanosoma cruzi of different genetic groups.

Lyzed epimastigotes of Trypanosoma cruzi clones P209-1, Gamba1, Sp104-1, MASu, Y7/1, MN12, Cl-Brener, 86/2036, Y7/2-1 inhibit the growth of Ehrlich adenocarcinoma in mice. the tumor decreased 1.5-3 times after 12 daily injections of lysates from 15 million epimastigotes. The protective effect progressed after the injections were discontinued and depended on the dose and lysate producer clone. Trypanosoma lysates in the studied doses were nontoxic.

Surface adhesins of lactobacilli loosely connected to the cell wall and eliminated into the environment during culturing in liquid nutrient media.

Six lactobacillus species and 4 clones of one of them were studied in order to clear out the ratio between the adhesion capacities of concanavalin A-reactive glycoprotein adhesins on the surface of the bacterial cell and glycoprotein adhesins released into the broth during culturing in liquid nutrient media. The adhesive activity of cultures is largely determined by the strain rather than species appurtenance. Elimination of glycoprotein adhesins from the bacterial cell and their antagonistic activity towards Candida albicans were demonstrated in specific interactions of glycoprotein adhesins with immune serum and concanavalin A.

[Immunization against Trypanosoma cruzi and tumor growth in mice].

The evidence has been produced that immunological mechanisms are involved in the known anticancer phenomenon of T. cruzi. Non-inbred albino mice were immunized with avirulent cultures of three strains and seven clones and then transplanted a tumor--sarcoma-180 or Ehrlich's adenocarcinoma. The used cultures induced the generation of T. cruzi antibodies whose level peaked by postimmunization days 50-60: the titers being 1:40-1:80 and the spread among the mice being 60%. Concurrently, immunization against T. cruzi provided a certain oncoprotective effect. In the immunized mice, the sizes of sarcoma-180 and adenocarcinoma were 1.5-2.0 and 2.0-2.5 times, respectively, less than those in the non-immunized ones. The antitumor protection was directly related to the murine blood T. cruzi antibody level during which implantation of a tumor occurred. At the peak of an immune response, the effect was 2 times higher than that in the early postimmunization periods. T. cruzi strains that were more immunogenic than clones ensured a more significant oncoprotection. The latter was more considerable in mice having antibody titers of 1:40-1:80 than in those with antibody titers of 1:10-1:20 and particularly in the animals showing no humoral response to the administration of the parasites at all.

Methodological approaches to detection of Tamm-Horsfall protein.

A new test system for measuring Tamm-Horsfall protein was developed. The system consists of antigenic diagnostic agent and immune serum. The specificity and sensitivity of the reagents were determined. The system was tested on 52 urine samples from subjects without renal diseases.