Function of the antioxidant system in rats exposed to cadmium

Lipid peroxidation (LPO) and antioxidant system functioning in the blood, liver and small intestine mucosal cells of rats under cadmium chloride intake and administration of the liposomal form of the biologically active supplement (BAS FLP-MD) have been studied. It is shown that cadmium chloride administration (1 mg/kg, 14 days) leads to the activation of the oxidative processes in the cells and decrease of the antioxidant enzyme activities including mitochondrial enzymes. The revealed inhibition of the hepatic superoxide dismutase (SOD) activity considerably determined by the effect on mitochondrial Cu, Zn-SOD. The effect of one-shot and long-term cadmium intake on the conjugation system and decrease of the tissue glutathione level were shown. BAS FLP-MD intake normalizes the oxidative processes possibly due to stabilization of the cellular components.     

Isolation and characterization of lectin from the surface of Grifola frondosa (FR.) S.F. Gray mycelium

For the first time, from the surface of the dikaryotic mycelium of the xylotrophic basidiomycete Grifola frondosa 0917 a lectin has been isolated with a molecular mass of 68 +/- 1 kDa, consisting of two subunits of 33-34 kDa each. The lectin is a hydrophilic glycoprotein with the protein : glycan ratio of 3 : 1. It exhibits high affinity to native rabbit erythrocytes and to human erythrocytes of the 0 blood group, but not to trypsin-treated ones. The hemagglutination (HA) caused by lectin was not blocked by any of the 25 tested mono-, di-, and amino sugars; it was also not blocked by some of glyco derivatives. Only 13.9 microg/ml of the homogeneous preparation of a polysaccharide, a linear D-rhamnan with the structure of the repetitive component --> 2)-beta-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 3)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> 2)-alpha-D-Rhap-(1 --> blocked hemagglutination completely. The analysis of the amino acid composition of the lectin showed the greatest percentage of amino acids with positively charged R groups, arginine, lysine, and histidine, as well as the complete absence of sulfur-containing amino acids, cysteine, and methionine. D-glucose and D-glucosamine were detected in the carbohydrate part.     

Characterization of plant phenolic compounds by cyclic voltammetry

Phenolic acids and flavonoids were characterized by cyclic voltammetry and total antioxidant activity in the reaction with the ABTS cation radical. Anode peak voltages (E_ap) and their pH dependences were determined for the studied phenolic acids and flavonoids. The E_ap and Trolox equivalent antioxidant capacity (TEAC) values were found to correlate for polyphenols, which react with the ABTS cation radical in two steps. Correlation between the half-wave potential (E_1/2) and TEAC was determined for electrochemically irreversible compounds. Mechanisms of the reaction of phenolics on the electrode involving one-and two-electron oxidation are proposed.     

Characterization of plant phenolic compounds by cyclic voltammetry

Phenolic acids and flavonoids were characterized by cyclic voltammetry and total antioxidant activity in the reaction with the ABTS cation radical. Anode peak voltages (Eap) and their pH dependences were determined for the studied phenolic acids and flavonoids. The Eap and Trolox equivalent antioxidant capacity (TEAC) values were found to correlate for polyphenols, which react with the ABTS cation radical in two steps. Correlation between the half-wave potential (Ep/2) and TEAC was determined for electrochemically irreversible compounds. Mechanisms of the reaction of phenolics on the electrode involving one- and two-electron oxidation are proposed.     

Ebola hemorrhagic fever: Properties of the pathogen and development of vaccines and chemotherapeutic agents

Molecular Biology - Ebola hemorrhagic fever (EHF) epidemic currently ongoing in West Africa is not the first among numerous epidemics in the continent. Yet it seems to be the worst EHF epidemic...     

On the role of carbohydrate-protein highly selective interactions in the biological activity of glycoconjugates: <Emphasis Type="Italic">Grifola frondosa</Emphasis> (Fr.) S.F. Gray lectin binding to specific and non-specific antibodies

Both quantitative and qualitative estimations of the basidiomycete Grifola frondosa lectin binding to the specific and non-specific polyclonal rabbit antibodies were attempted. The lectin complexation with homological antibodies was shown to be characterized by greater binding constants as compared to non-homological antibodies. Therewith the values of changes in standard free energy ∆G ⁰ displaying a strength of both complexes were essentially the same. The data obtained testify to universality of biospecific reactions “antigen–antibody” and “lectin–carbohydrate” at a molecular level, and could give new insight into the phenomenon of these biospecific interactions. The actual specificity in the above bio-recognition processes could differ from the results of in vitro assays using lectins, and, therefore, should be interpreted carefully when concluding on the lectins behaviour in living systems.     

Virulent properties of hospital strains of bacteria of the Burkholderia cepacia complex, isolated in hospitals of Moscow

The results of the study of hospital strains of the B. cepacia complex, isolated in hospitals of Moscow, with the use of phenotypical and molecular-genetic methods are presented. The phenotypical methods made it possible to differentiate Russian strains and classify them with a group of genomovars (I, III, IV). As the result the epidemic importance of the strains with epidemic markers, having specific characteristics for every clinic, was determined. The detection of the collection of genes cepI and cepR in the strains made confirmed the epidemic importance of the stains which had, due to the regulatory "quorum sensing" (QS) system, the potential capacity for inducing infection and persisting in the patient's body. The presence of gene cepR in all strains and the absence of gene cepl in 33% of strains gave evidence to suggest that in some strains the activation of the production of pathogenicity factors required the presence of other bacteria having the fully developed QS system. Thus, the new complex approach with the use of phenotypical and molecular-genetic methods permits more precise identification of the source of hospital infection induced by the bacteria of the B. cepacia complex.