The effect of changes in CYP2E1 activity in the liver on toxicity and carcinogenicity of diethylnitrosamine in mice

In this work, the biological effects of diethylnitrosamine (DENA) have been studied under controlled conditions of its metabolism in mice of different ages. The results indicate that the general toxic and hepatocarcinogenic effects of DENA are mostly due to the parent compound, whereas the alkylating metabolites cause hepatic cell damage. Our findings cast doubt on the conventional understanding of the exclusive role of mutagenic activation in the carcinogenic action of chemicals.     

Comparison of Influenza Outbreaks in the Republic of Kazakhstan and Russia Induced by 2009 Yearly New Variant of А(H1N1) Influenza Virus

The aim of the work is the comparison of the epidemiology of influenza and acute respiratory virus infections (ARVI) in the Republic of Kazakhstan with the corresponding influenza epidemic in Russia induced by influenza pandemic virus A/California/07/2009 in 2009.Data on influenza and ARVI from the Republic of Kazakhstan and Federal Center of influenza was collected and investigated over the course of several weeks from hospitalized patients with the same diagnosis among all population and in age groups on ...     

Functional changes in the snail statocyst system elicited by microgravity

Background

The mollusk statocyst is a mechanosensing organ detecting the animal''s orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations.

Methodology/Principal Findings

In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.), (ii) the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L.), and (iii) the differential expression of the Helix pedal peptide (HPep) and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.). Experiments were performed 13–42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed.

Conclusions/Significance

Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism''s ability to adapt to gravity changes. This simple animal model offers the possibility to describe general subcellular mechanisms of nervous system''s response to conditions on Earth and in space.     

Abscisic acid – an intraleaf water-stress signal

Physiological aspects of abscisic acid (ABA) as a drought signal directed specifically at guard cells are topical research foci. Most investigations concentrate on the importance of remote sources of ABA against the background knowledge that leaves are also a source of ABA. Foliar compartmentation of ABA and water-stress-induced release of cellular ABA into the apoplast imply additional levels of complexity. In the present study, we established that the pre-existing foliar ABA pool can be moved to guard cells. We detached leaflets of Vicia faba L. to eliminate an external source of ABA. The leaflets were then pretreated with cycloheximide (CHI), an inhibitor of protein biosynthesis that abolished ABA accumulation in the leaflets. Next, the leaflets were water stressed. After incubation, leaflets were snap-frozen and freeze-dried. Guard cells were individually dissected from the leaflets; such guard-cell samples contain both apoplastic and symplastic ABA. The ABA content of guard cells of CHI-treated, water-stressed leaflets was less than that of control water-stressed leaflets, but higher than that of control water-sufficient leaflets, indicating that guard cells are targets of intraleaf ABA redistribution under stress.     

The appraisal of the level of photo- and peroxide resistance of human erythrocytic and lymphocytic cells in presence of biogenic amines

The changes of photo- and peroxide resistance of erythrocytic and lymphocytic cells of human under influence of UV and some active oxygen forms in presence of biogenic amines such as serotonin, dopamine, adrenalin, histamine had been investigated. While investigating the degree of photohemolysis of erythrocytes it was discovered that biogenic compounds raise UV stability of erythrocytic membranes. By using the method of chemiluminescence it was established that biogenic amines increased the degree of peroxide resistance of human erythrocytic and lymphocytic cells. The decrease of the level of erythrocytic diene conjugates under influence of UV by serotonin and histamine was also discovered.