[Correlation of codon biases and potential secondary structures with mRNA translation efficiency in unicellular organisms].

UNLABELLED: Gene expression is known to correlate with degree of codon bias in many unicellular organisms. However, such correlation is absent in some organisms. Recently we demonstrated that inverted complementary repeats within coding DNA sequence must be considered for proper estimation of translation efficiency, since they may form secondary structures that obstruct ribosome movement. We have developed a program for estimation of potential coding DNA sequence expression in defined unicellular organism using its genome sequence. The program computes elongation efficiency index. Computation is based on estimation of coding DNA sequence elongation efficiency, taking into account three key factors: codon bias, average number of inverted complementary repeats, and free energy of potential stem-loop structures formed by the repeats. The influence of these factors on translation is numerically estimated. An optimal proportion of these factors is computed for each organism individually. Quantitative translational characteristics of 384 unicellular organisms (351 bacteria, 28 archaea, 5 eukaryota) have been computed using their annotated genomes from NCBI GenBank. Five potential evolutionary strategies of translational optimization have been determined among studied organisms. A considerable difference of preferred translational strategies between Bacteria and Archaea has been revealed. Significant correlations between elongation efficiency index and gene expression levels have been shown for two organisms (S. cerevisiae and H. pylori) using available microarray data. The proposed method allows to estimate numerically the coding DNA sequence translation efficiency and to optimize nucleotide composition of heterologous genes in unicellular organisms. AVAILABILITY: http://www.mgs.bionet.nsc.ru/mgs/programs/eei-calculator/.

[Mechanisms of the therapeutic effect of hyperbaric oxygenation in minor differential pressure in stroke]. / O mekhanizme lechebnogo deistviia giperbaricheskoi oksigenatsii pri malom izbytochnom davlenii pri mozgovom insul'te.

Analysis is made of a complex of clinicoelectrophysiologic, biochemical and biophysical studies conducted in 220 patients with brain stroke, receiving a course of hyperbaric oxygenation (HBO) at minor differential pressure (1.2-1.3 absolute atmospheres). It is shown that HBO can be applied as pathogenetic therapy in patients afflicted with brain stroke. It produces a marked clinical effect and normalizes EEG, REG and acid-alkaline balance, brings about a decrease of initially high lipid peroxidation (LPO), activating antioxidative processes and superoxide dismutase. However, such an effect is only produced by the first HBO sessions at minor differential pressure, which is likely to be due to the substitution action of hyperoxia and activation of antioxidative processes. The studies thus made validate the efficacy of short-term sessions of HBO in patients with brain stroke and the possibility of hyperoxia over-dosage in patients with disturbed antioxidant defence.