Effect of Panavir on influenza A virus reproduction]

Mitogenic properties of panavir, as well as its effect on the grippe virus reproduction in cell systems in vitro and the effect on the survival of mice with the experimental grippe infection were studied. It was shown that panavir had no cytotoxic action whereas it was characterized by pronounced mitogenic activity and subsequently could be considered as a perspective immunomodulator. Under in vitro conditions with the use of relatively high doses for the cell contamination with the grippe virus, panavir lowered the virus production in the cell systems. When the contaminating doses were low, panavir inhibited the virus production detected at the early stages of the infection. In the in vivo studies on mice with the experimental grippe infection panavir showed antigrippe activity against both the romantadine resistant and the remantadine nonresistant populations of the grippe A virus.     

Expression of hormonal carcinogenesis genes and related regulatory microRNAs in uterus and ovaries of DDT-treated female rats

The insecticide dichlorodiphenyltrichloroethane (DDT) is a nonmutagenic xenobiotic compound able to exert estrogen-like effects resulting in activation of estrogen receptor-α (ERα) followed by changed expression of its downstream target genes. In addition, studies performed over recent years suggest that DDT may also influence expression of microRNAs. However, an impact of DDT on expression of ER, microRNAs, and related target genes has not been fully elucidated. Here, using real-time PCR, we assessed changes in expression of key genes involved in hormonal carcinogenesis as well as potentially related regulatory oncogenic/tumor suppressor microRNAs and their target genes in the uterus and ovaries of female Wistar rats during single and chronic multiple-dose DDT exposure. We found that applying DDT results in altered expression of microRNAs-221, -222, -205, -126a, and -429, their target genes (Pten, Dicer1), as well as genes involved in hormonal carcinogenesis (Esr1, Pgr, Ccnd1, Cyp19a1). Notably, Cyp19a1 expression seems to be also regulated by microRNAs-221, -222, and -205. The data suggest that epigenetic effects induced by DDT as a potential carcinogen may be based on at least two mechanisms: (i) activation of ERα followed by altered expression of the target genes encoding receptor Pgr and Ccnd1 as well as impaired expression of Cyp19a1, affecting, thereby, cell hormone balance; and (ii) changed expression of microRNAs resulting in impaired expression of related target genes including reduced level of Cyp19a1 mRNA.     

Differences in activation of the motoneurone inhibitory receptors in a frog Rana ridibunda by GABA and glycine and their interaction

The membrane potential responses evoked by GABA and glycine bath applications were studied intracellularly in the motoneurons of the isolated frog spinal cord. The amplitude of glycine-evoked responses was 1.5-2.0 larger than that of GABA-evoked response at the same concentration. EC50 were 0.75 mM and 1.57 mM for glycine and GABA, respectively. The amplitude of responses induced by the simultaneous applications of both agonists were 79.1 +/- 2.4% (n = 19) of the sum of individual responses and 130.1 +/- 1.5% (n = 19) of individual glycine-induced responses (partial occlusion). GABA-evoked responses were decreased by 85.3 +/- 0.2% (n = 10) as a result of glycine preliminary application while preapplication of GABA reduced glycine-evoked responses only by 52.9 +/- 0.3% (n = 11). Glycine- and GABA-evoked responses were selectively suppressed by strychnine and bicuculline, respectively. These results suggest that amphibian spinal motoneurones express (less specifically than those of mammals) both glycine (predominantly) and GABAA receptors, with asymmetric cross-inhibition possibly taking place in them.     

Left-ventricular heart aneurism as a new source of resident cardiac stem cells

In the past few years, it has been established that the heart contains a reservoir of stem and progenitor cells. These cells are able to differentiate in cardiomyogenic, endothelial, and smooth muscle lineages in vitro and in vivo and, following injection into an infarcted myocardium, these cells prevent the remodeling of the left ventricle and improve cardiac function. The aim of the present study was the immunophenotypic characterization of resident stem cells in the tissue of a chronic left aneurism, an analysis of their localization, and distribution in various aneurism areas.     

Behavior in the forced-swimming test and expression of BDNF and Bcl-xl genes in the rat brain

A single exposure of rats to the forced-swimming stress decreased BDNF mRNA levels in the cortex and increased Bcl-xl gene expression in the hippocampus and amygdala 24 h after the stress. The animals demonstrated a depressive-like behavior and elevated blood corticosterone level. There was a significant negative correlation between BDNF mRNA level in the cortex and immobility time during swimming. Repeated exposure to swimming stress caused the elevation of the hippocampal BDNF mRNA level assessed 24 h after the second swimming session. The data suggest that stress-induced down-regulation of cortical BDNF gene expression and behavioral despair in the forced-swimming test may be interrelated. The increase in the BDNF and Bcl-xl mRNA levels may contribute to the mechanisms protecting the brain against negative effects of stress.     

Combining ability for the traits of stem branching and plant height in linseed lines

Combining ability for the traits of stem branching and plant height has been studied in ten pure lines of flax under complete and incomplete diallel crosses. High heritability of the traits "plant height", "the number of lateral stems" and "the number of lateral shoots" and essential role of genes with dominant effects of interaction in genetic control of the traits of stem branching and plant height have been shown. On the basis of combining ability indexes the ways for usage of certain genotypes and crossing combinations in flax breeding were defined. As a result of individual selection from hybrid combinations some new complexes of habit traits and agriculturally valuable plant characteristics were obtained.     

Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids

Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT) neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg), and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg). Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.     

Involvement of 5-HT1 and 5-HT5A Receptors in Modulation of Synaptic Transmission and Intrinsic Membrane Properties of Spinal Motoneurons of the Frog (Rana ridibunda)

Journal of Evolutionary Biochemistry and Physiology - The endogenous monoamine serotonin (5-HT) is involved in the modulation of motor output in vertebrates by interacting with different types of...