Delayed Consequences of the Toxic Effect of Paclitaxel on the Testes of Prepubertal Rats and Their Correction with p-Tyrosol.

Delayed gonadotoxic effects were revealed in outbred male sexually mature rats (SD) after exposure to paclitaxel in the prepubertal period, and the possibility of their correction with p-tyrosol was shown. It was found, that administration of paclitaxel does not inhibit the ability of animals to conceive, but impairs the reserve capacity of the testicular tissue. In intact female rats crossed with male rats receiving paclitaxel, increased post-implantation fetal death was observed. Combined administration of paclitaxel and p-tyrosol alleviated the delayed effects of the cytostatic treatment on the prepubertal testis.

Estimation of the Regenerative Potential of para-Tyrosol in the Model of Testicular Insufficiency Caused by Damage to Spermatogonial Stem Cells.

The regenerative properties of p-tyrosol were investigated in a model of testicular insufficiency caused by a toxic effect on spermatogonial stem cells (single administration of paclitaxel in the maximum tolerable dose). Against the background of p-tyrosol administration, we observed an increase in the number of normal spermatogonia and Sertoli cells, stimulation of spermatogenesis, and renewal of the spermatogenic tissue. The treatment with p-tyrosol also led to a decrease in DNA damage in cells of the testicular tissue. These changes were accompanied by a decrease in the level of free radicals, an increase in antioxidant protection, and normalization of the redox potential.

Experimental Evaluation of Long-Term Toxic Effects of Methotrexate on Male Reproductive System.

The morphological and functional state of the reproductive system was studied in male outbred rats (SD stock) and male F1(CBA×C57BL/6) mice after long-term (3 months) methotrexate administration. The drug was administered subcutaneously once a week for 4 weeks, the dose for male rats was 1 mg/kg, for male mice 2.2 mg/kg. It was found that male rats retained the ability to conceive, their reproductive potential was not limited by increased risk of embryo death. At the same time, signs of astheno- and pathospermia were revealed. The testicular tissue was characterized by reduced content of the sources of the proliferative pool of spermatogenesis. In mice treated with methotrexate, increased content of DNA breaks was detected in the testicular cells.

Evaluation of the Effect of p-Tyrosol on the Level of DNA Damage in the DNA Comet Assay In Vivo.

The effect of p-tyrosol on the spontaneous level of DNA damage in the cells of the bone marrow, liver, kidney, and rectum of mice (series I) and on the genotoxic effects of cytostatic drugs with different mechanisms of action in rat testicular cells (series II) was studied by DNA comet assay on C57BL/6 mice. p-Tyrosol was administered in a dose of 40 mg/kg once (series I) or for 5 days before and 5 days after cytostatic exposure (busulfan, paclitaxel, methotrexate; series II). It was found that p-tyrosol reduced spontaneous level of DNA damage in all studied organs. p-Tyrosol exhibited an antigenotoxic effect with respect to the DNA-damaging action of methotrexate and produced no genoprotective effect in case of busulfan and paclitaxel.

Effectiveness of Phenolic Antioxidants in Experimental Model of Benign Prostatic Hyperplasia.

Experimental model of sulpiride-provoked benign prostatic hyperplasia was employed to comparatively assess the effect of phenolic antioxidants (dihydroquercetin, p-thyrozol, dibornol, and prostagenin) on prostate morphology. All examined agents decreased the degree of hyperplasia in acinar epithelium; the greatest efficacy was demonstrated by prostagenin. Moreover, dihydroquercetin and p-thyrozol increased the cross-section area of acinar lumina and prostate volume, which is inadmissible in this pathology. These results suggest that the use of phenolic antioxidants in the therapy of benign prostatic hyperplasia should be strictly controlled.

Evaluation of Kagocel Genotoxicity.

Antiviral drug Kagocel in concentrations of 0.0008, 0.004, 0.02, 0.1, 0.5, and 2.5 mg/ml with or without metabolic activation does not induce gene mutations in S. typhimurium strains ТА98, ТА100, ТА1535, and ТА1537 and in a combination of E. coli strains pKM101 and uvrA. A single intragastric administration of Kagocel in a daily therapeutic dose and a 10-fold daily therapeutic dose to male mice or multiple administrations in daily therapeutic dose to male and female mice did not led to a significant increase in the percentage of chromosomal aberrations in the bone marrow cells. DNA comet assay revealed no significant increase in the incidence of DNA breaks in cells of mouse testes after single or multiple administration of Kagocel at daily therapeutic and 10-fold daily therapeutic doses. Our results indicate that Kagocel exhibits no genotoxic activity in the studied dose range.

Experimental Study of the Effectiveness of Phenolic Antioxidants in Male Infertility Caused by Pathospermia.

The effect of phenolic antioxidants (dihydroquercetin, p-tyrosol, dibornol) on the morphology, functions, and redox processes in the reproductive cells of male rats was studied on the model of experimental pathospermia. All antioxidants reduced the percentage of degenerative forms of spermatozoa. Dibornol was most effective. Dihydroquercetin and p-tyrosol did not increase the total number of spermatozoa and the percentage of their mobile forms. These indicators were improved only by dibornol. After administration of all test drugs, the antioxidant potential of spermatozoa increased and did not significantly differ from the baseline values.

Dihydroquercetin effects on the morphology and antioxidant/prooxidant balance of the prostate in rats with sulpiride-induced benign hyperplasia.

A course of dihydroquercetin (antioxidant) injections to 5-month-old Wistar rats with sulpiride-induced benign prostatic hyperplasia led to reduction of proliferative activity in the glandular structures and to attenuation of the inflammatory reaction in the tissue. Prostatic antioxidant/prooxidant balance returned to normal after the treatment.

[Evolutionary variability of influenza B viruses in Russian Federation in 2005-2012].

Specific traits of influenza B viruses circulation in Russia and worldwide in 2005-2012 were studied and the amount of influenza B viruses in the whole population of influenza viruses isolated in Russia was estimated. The trend toward antigenic drift for both Victoria and Yamagata lineages was characterized. The genetic analysis revealed amino acid changes that influenced the antigenic properties of the viruses. The match of the epidemic isolates and vaccine strains was corroborated.

[The 2009 pandemic influenza in Russia. I. Diagnosis and molecular biological characteristics of the virus].

The analysis of 1558 clinical samples revealed influenza virus A(H1N1v) RNA in 339 patients with influenza and 163 fatal cases,which was made in May to December 2009. Data on the antigenic properties of more than 250 of pandemic virus strains isolated at the Research Institute of Influenza and the molecular genetic characteristics of 31 strains are presented. All the test isolates were found to have the S203 substitution in hemagglutinin, which was characteristic of one of 5 minor genome A(H1N1v) virus variants found in the United States and Mexico in 2009. All the test strains contain the S31N substitution in the M2 protein, which determines viral resistance to adamantine, and have no H275Y substitution in neuraminidase, which determines oseltamivir resistance. The substitution of amino acid residue of Asp to Gly at position 222 of HA was found in 8 (73%) of 11 isolates from postmortem lung and trachea samples and in 2 (10%) of 20 isolates from nasopharyngeal swabs. The determination of the pathogenic role of this substitution calls for further investigations.

[Etiological characteristics of the influenza epidemics of 2006-2009 in the Russian Federation (according to the data of the Research Institute of Influenza, North-Western Branch, Russian Academy of Medical Sciences)].

The basic trends in the evolution of influenza A and B in the Russian Federation during the epidemic seasons of 2006-2009 were studied on the basis of an antigenic analysis of 1774 Influenza isolated at the Research Institute of Influenza (RII), North-Western Branch, Russian Academy of Medical Sciences, and sent from resting bases (the regional centers of the Russian Inspectorate for the Protection of Consumer Rights and Human Welfare, which collaborate with the RII). Although the trends in the substitution of representative strains generally coincide with the world patterns, the authors revealed some specific features of the antigenic drift of influenza viruses in the Russian Federation and regional varieties. Data on some biological properties and those of the antigenic analysis of the first pandemic influenza A(H1NI)v strains isolated at the RII from Saint Petersburg patients in July-August 2009 are also given in the paper.

[Molecular characteristic of influenza virus A H5N1 Strains isolated from poultry in Kurgan Region in 2005].

During the latter half of 2005 a widespread outbreak caused by influenza highly pathogenic H5N1 virus among wild and domestic birds occurred in Russia. As pathogenicity level is a polygenic feature and majority of individual genes of influenza A viruses contribute to pathogenicity of influenza viruses to birds, animals and humans. Nucleotide sequencing of the entire genome of influenza H5N1 virus isolates obtained in Kurgan region (Western Siberia) was performed. Structure of viral proteins was analyzed according to the predicted amino acid sequences. HA receptor-binding site of A/chicken/Kurgan/05/2005 and A/duck/Kurgan/08/2005 strains was typical for avian influenza viruses and contained Glu and Gly at positions 226 and 228, respectively. Structure of the cluster of positively charged amino acid residues at the cleavage site was identical for all isolates: QGERRRKKR. According to the data of neuraminidase structure analysis NA of the H5N1 isolates tested was suggested to belong to Z genotype. Amino acid residues typical for birds were revealed in 30 out of 32 positions of M1, M2, NP, PA and PB2 proteins determining host range specificity. One strain isolated in Kurgan contained lysine in position 627 of PB2 protein. Kurgan isolates was shown to have remantadine-sensitive genotype. Glutamic acid was found at position 92 of NS1 protein in both strains indicating virus resistance to interferon. Phylogenetic analyses allowed relating Kurgan isolates to subclade II of clade II of highly pathogenic H5N1 influenza viruses.

[Epizootics of "avian" influenza as the manifestation of pandemic].

In this review of literature modern notions on the role of birds in the evolution of the pathogenicity signs and immune system of the main and intermediate hosts of influenza viruses, as well as on the mechanisms of overcoming interspecific barriers, are analyzed. The chronology of the spread of "avian" influenza among humans, starting from 1997, the properties of the natural reservoir of this infection, and in particular influenza viruses A, the ways of their variability and evolution are presented. The conclusion has been made that the mixing, joint evolution, recombination and reassortment of viral genomes may be caused by global events in individual geographical regions.

[Effect of cAMP-dependent phosphorylation on the activity of Mg2+,Ca2+-ATP-ase and Ca2+ transport in the sarcoplasmic reticulum of the white skeletal muscles of the rabbit]. / Vliianie cAMP-zavisimogo fosforilirovaniia na aktivnost' Mg2+,Ca2+-ATP-azy i transport Ca2+ v sarkoplazmaticheskom retikulume belykh skeletnykh myshts krolika.

It is shown that endogenic phosphorylation of sarcoplasmatic reticulum membranes in white skeletal muscles of rabbit stimulates Mg2+, Ca2+-ATPase activity and Ca2+ accumulation. When the level of endogenic phosphorylation is high, exogenic cAMP and protein kinase do not affect Mg2+, Ca2+-ATPase activity, when the level is low, they produce a 1.5-2-fold increase in the activity. The inhibitor of cAMP-dependent protein kinase practically completely eliminates the effect of endogenic phosphorylation on Ca2+ accumulation and Mg2+, Ca2+-ATPase activity. Under endogenic phosphorylation the Ca2+ binding constant becomes 1.8 times as low in sites of high affinity for this ion, and 4 times as low--in sites of low affinity.

[Endogenous phosphorylation of sarcoplasmic reticulum fragments of rabbit fast skeletal muscles]. / Endogennoe fosforilirovanie fragmentov sarkoplazmaticheskogo retikuluma bystrykh skeletnykh myshts krolika.

The purified membrane fragments of sarcoplasmic reticulum (SR) of rabbit fast skeletal muscles were found to incorporate 32P from[gamma-32P]ATP in endogenous membrane substrates and in histone H1. The existence of membrane-bound protein kinase of SR was demonstrated by steady state binding of [3H]-cAMP to the SR membranes. The constant of [3H]cAMP binding to the membranes is 2.5 +/- 0.003 x 10(6) M-1, the number of binding sites is 6.1 +/- 0.8 pmol per 1 mg of protein. The endogenous phosphorylation of SR components was inhibited by cAMP and cGMP at concentrations of 10(-7)-10(-6) and depended on Mg2+ and Ca2+. The thermostable protein inhibitor of cAMP-dependent protein kinase inhibited the endogenous phosphorylation of SR membranes by 30-40%. The protein phosphoproduct of SR membranes revealed the properties of a phosphoester. The membrane-bound protein kinase was active towards the exogenous substrate--histone H1. Phosphorylation in the presence of histones was independent of cyclic nucleotides, Mg2+ and Ca2+. Fractionation of 32P-labelled solubilized membranes in polyacrylamide gel in the presence of Na-SDS showed that the radioactivity is bound to protein zones with molecular weights of 95 000 and 6000.

[Valuable contribution to the biochemistry of muscles (A. I. Silikova)]. / Tvorcheskii vklad v biokhimiiu myshts.

The paper deals with the results of scientific activity of A. I. Silakova (1908-1980) The main data are presented obtained by A. I. Silakova concerning the physiological role and transformation ways of glutamine in the muscular tissue. Her achievements are marked in development of some techniques, the isolation of pure fraction of muscular nuclei in particular, which create the necessary prerequisites for extending the research of biochemical processes in muscular nuclei and their membranes.

[ATPase activity and processes of calcium transport in membranes of sarcoplasmic reticulum of skeletal muscles with E-avitaminotic dystrophy]. / Mg 2+, Ca 2+--ATPaznaia aktivnost' i protsessy transporta kal'tsiia v membranakh sarkoplazmaticheskogo retikuluma skeletnykh myshts pri E-avitaminoznoi distrofii.

Peculiarities of functioning of the sarcoplasmic reticulum muscles membranes with E-avitaminotic distrophy were studied. It was determined that the level of ATP-dependent consumption of Ca2+, value of the Mg2+, Ca2+-ATPase activity and an amount of the intermediate phosphorylated product forming in the reaction of ATP hydrolysis decrease. The rate of this product formation in the sarcoplasmic reticulum of the distrophic muscles is inhibited as compared to normalcy. Elimination of Ca2+ into calcium-free medium from the vesicular membranes of the reticulum preliminarily loaded with Ca2+ occurs more rapidly under dystrophy than in normalcy. The data obtained evidence for a disturbance of mechanism of Ca2+ active transport and for an increase in the membrane permeability for Ca2+ in the membranes of the dystrophic muscles sarcoplasmic reticulum. A problem is considered on a dependence of the skeletal muscles observed in the reticulum under dystrophy of the functional changes on the membrane structure, in particular on their lipid composition.