Study of the mechanism of initiation of enzymatic NADPH-dependent lipid peroxidation in membranes of the endoplasmic reticulum

The localization and mechanism of generation of active oxygen species in the enzymatic NADPH-dependent lipid peroxidation system in liver microsomes were studied. Using the spin-trapping method, the key role of active oxygen species in the initiation of NADPH-dependent enzymatic lipid peroxidation was confirmed. It was shown that active oxygen species are generated via consecutive one-electron reduction of the oxygen molecule by NADPH-cytochrome P-450 reductase.     

Correlation between the bone mass of athletes and biochemical and genetic markers of bone tissue remodeling

The association of the polymorphism of the VDR, Col1a1, and CALCR genes with a form of osteoporosis frequently occurring as a consequence of intense physical exercise in athletes was studied. Biochemical parameters of bone remodeling and its neuroendocrine regulation, as well as the bone masses, of 22 amateur athletes were determined immediately before a strenuous nine-week training cycle (TC) and eight months later. The possible association of these factors with the polymorphism of the genes coding for bone tissue proteins was studied. Long-term intense physical training was found to be associated with a significant activation of bone tissue resorption accompanied by continued rapid synthesis. Nevertheless, and in spite of the strong activation of resorption caused by the TC, the athletes exhibited no osteoporosis (even eight months after the discontinuation of the TC); some of them, however, displayed an individual tendency to osteopenia. According to the results of genetic analysis, this was associated with the polymorphism of predisposition genes (genotype TT of the VDR gene and the functionally weakened s allele of the Col1a1 gene).     

The Effects of a Low-Frequency Electric Field on Recombinant Luciferase Activity

Biophysics - Studies on the effects of an electromagnetic field on the activity of recombinant luciferase in the luciferase–luciferin–ATP-Mg2+ system were conducted. The enzymatic...     

The Relationship between the Structure of the Tick-Borne Encephalitis Virus Strains and Their Pathogenic Properties

Tick-borne encephalitis virus (TBEV) is transmitted to vertebrates by taiga or forest ticks through bites, inducing disease of variable severity. The reasons underlying these differences in the severity of the disease are unknown. In order to identify genetic factors affecting the pathogenicity of virus strains, we have sequenced and compared the complete genomes of 34 Far-Eastern subtype (FE) TBEV strains isolated from patients with different disease severity (Primorye, the Russian Far East). We analyzed the complete genomes of 11 human pathogenic strains isolated from the brains of dead patients with the encephalitic form of the disease (Efd), 4 strains from the blood of patients with the febrile form of TBE (Ffd), and 19 strains from patients with the subclinical form of TBE (Sfd). On the phylogenetic tree, pathogenic Efd strains formed two clusters containing the prototype strains, Senzhang and Sofjin, respectively. Sfd strains formed a third separate cluster, including the Oshima strain. The strains that caused the febrile form of the disease did not form a separate cluster. In the viral proteins, we found 198 positions with at least one amino acid residue substitution, of which only 17 amino acid residue substitutions were correlated with the variable pathogenicity of these strains in humans and they authentically differed between the groups. We considered the role of each amino acid substitution and assumed that the deletion of 111 amino acids in the capsid protein in combination with the amino acid substitutions R16K and S45F in the NS3 protease may affect the budding process of viral particles. These changes may be the major reason for the diminished pathogenicity of TBEV strains. We recommend Sfd strains for testing as attenuation vaccine candidates.     

Defatting and Clarification of Protein Hydrolysates by Using Chitosan Solutions

The possibility of the use of small amounts of chitosan for defatting and clarification of protein solutions prepared by enzymatic hydrolysis was tested. The following treatment conditions were shown to be optimal: a chitosan concentration range, from 1.0 to 1.5 gram per kilogram raw weight; pH of the precipitation medium from 8.0 to 8.5; and duration of the incubation of the protein hydrolysate solution with chitosan, less than 1 h. The hydrolysate defatting grade was found to depend on the degree of chitosan deacetylation. A possible mechanism of the chitosan-induced effects was suggested. The use of chitosan allows the mass fraction of enzyme protein hydrolysates to be reduced fourfold to fivefold.     

Antibiotic prophylaxis, antibiotic therapy and microbiological situation in surgical unit]

The clinical and economic efficacies of antibiotic prophylaxis in the surgical unit of the Hospital were confirmed by the results of the analysis of 1313 case records of the patients operated during a year for acute appendicitis and acute cholecystitis. At the same time it was shown advisable to use antibiotic therapy in the patients with various pathological processes. The dynamics of the microbial dissemination in the surgical unit and some other units of the Hospital, as well as the dynamics of antibiotic resistance of the microflora, its interrelation with the volume of the antibacterials used and their rotation are described.     

Roentgeno-functional study of the talocrural joint in the long-term follow-up of a fracture of the crural bone

On the basis of the results of clinicoroentgenological and tensographic investigations of 119 patients after traumas of the crural bones and ankle joint (2-36 yrs. ago) the authors showed the importance of roentgenofunctional investigation of the ankle joint, a patient being in a standing position with maximum flexion and extension of the foot. A specially designed footing was proposed. Of 77 patients after intra-articular fractures of the ankle bones various disorders in articular proportions, undetectable on routine roentgenography, were diagnosed in 29 by functional roentgenography. Articular changes on roentgenofunctional investigation were revealed in one patient only out of 42 patients with extra-articular fractures of the crural bones. Tensography showed disorders of foot biomechanics in all patients with subluxations in the ankle.     

Comparison of the action of pristan and Freund's incomplete adjuvant on the development of ascites in mice--the recipients of hybridoma cells

Production of immunodiagnostic preparations based on monoclonal antibodies requires large amounts of such antibodies. Most frequently preparative quantities of monoclonal antibodies are provided by ascitic fluid from hybridoma-carrying mice. Prior to intraperitoneal administration of hybridoma cells mice are subjected to stimulation with pristan, a mineral oil component. The authors showed that the Freund's incomplete adjuvant (FIA) may be as well used for this purpose. The effect of pristan and the FIA on ascites development in mice with hybridomas producing monoclonal antibodies to the Ia-like antigens of man was studied. The stimulants were administered in amounts of 0.5 ml per a mouse. It was shown that irrespective of the stimulant injection time and the number of the administered hybridoma cells the amount of the ascitic fluid formed in female mice BALB/c stimulated with the FIA was 1.5-3 times higher as that in the animals stimulated with Pristane, the antibody titer in the ascitic fluid being unchanged.     

NMR study of the structural transition in the DNA-bound water system in the interval of physiological temperatures

Temperature dependence of spin-spin proton relaxation times of DNA and bound water and the content of bound water in the samples of DNA, saturated with water in the atmosphere with different relative humidities from 0 to 100% were studied by means of pulsed NMR. It is shown that the temperature transition in the system of DNA-bound water in the interval 18-35 degrees is observed only when the relative humidity is more than 70% and the double-stranded structure of DNA exists. The transition of DNA from one conformation into another passes through some intermediate state more labile and probably less ordered. This transition is accompanied by changes in the structure of the hydration shell. In the case when relative humidity is greater than 80%, the partial dehydration of DNA stimulated by the transition is observed. This dehydration increases with the increase of relative humidity.     

Test systems for biomonitoring based on membrane-bound enzyme complexes. V. Mixed-function monooxygenase induction in the liver microsomes of Lake Baikal fish

The content of cytochrome P450 and monooxygenase activity has been studied in the liver of Baikal fishes (Coregonus automnalis, Thymallus articus, Brachymystax lenok and Cottocomphorus greminsky). The administration of 3-methylcholanthrene increases considerably the level of metabolic activity of microsomal fraction and cytochrome P450 content in liver. The data of microsomal fractions of rats and fishes liver electrophoresis have shown that xenobiotic causes the synthesis of similar according to the molecular weight forms of cytochrome P450 in these animals. The induction of microsomal monooxygenase inhibits the lipid peroxidation of microsomal fraction.