Modification of hydrophobic sorbents by cobalt chloride in order to concentrate low molecular polar organic substances from the air for subsequent gas chromatographic determination.

The article presents a new method of modification of hydrophobic sorbents. To improve sorption pre-concentration of polar organic compounds in the air analysis, these sorbents are coated with cobalt chloride. This modification increases retention volume of lower alcohols by 5-10 fold as compared to that of unmodified sorbents and solves the problem of gas-chromatographic determination at 1-2 ppb (micrograms/m(3)) by using the most common flame ionization detector.

[The birth and death of genes].

Duplications of DNA regions with subsequent divergence of the duplicated copies by mutations is traditionally considered to be the major mechanism of the new genes appearance. After duplication, only a small fraction of the paralogs remains unchanged, while most copies are converted into pseudogenes or acquire new functions as a consequence of either subfunctionalization or neofunctionalization events. In some cases, certain regions of duplicated copies can combine with each other, giving rise to functionally new genes.

[Modification of [PSI+] prion properties by the combination of amino acid changes within Sup35 protein N-domain].

[PSI+] prion is an amyloid isoform of a release factor Sup35p (eRF3). The structure of these protein aggregates remains unclear despite a long term history of prion amyloids investigations. The N-terminal domain of Sup35p (which is responsible for a propagation of prion) shapes superpleated beta-structure, according to modern concepts.

[The identification of Saccharomyces cerevisiae genes leading to synthetic lethality of prion [PSI+] with Sup45 mutations].

Previously, we proposed a test system allowing to perform search for genes that influence the properties of the Sup35 and Sup45 protein. This test is based on the phenomenon of lethality of diploids that combine mutations in SUP45 gene with [PSI+] prion. Lethality of this combination depends on the type of sup45 mutation, and the properties of the prion.

[The influence of UPF genes on the severity of SUP45 mutations].

Eukaryotic cells possess special mechanism of the degradation of mRNAs containing premature termination codons (PTCs)--nonsense-mediated mRNA decay (NMD) pathway. In yeast Saccharomyces cerevisiae, the activity of this pathway depends on the recognition of the PTC by the translational machinery and interaction of translation termination factors eRF1 and eRF3 with Upf1, Upf2 and Upf3 proteins. Previously we have shown that decreasing of eRF1 amount causes an impairment of NMD.

[Overexpression of genes encoding tRNA(Tyr) AND tRNA(Gln) improves viability of nonsense mutants in SUP45 gene in yeast Saccharomyces cerevisiae].

The variety of mechanisms providing viability of organisms bearing nonsense-mutations in the essential genes is unknown at present. In yeast Saccharomyces cerevisiae nonsense-mutants containing premature stop-codon in mRNA of the essential SUP45 gene were obtained. These strains are viable in the absence of mutant suppressor tRNA, therefore it is supposed that there are alternative mechanisms providing nonsense-suppression and mutants viability.

[Mutations in the Sup35 gene impairs degradation of mRNA containing premature stop codons].

Eukaryotic cells possess special mechanism of the degradation of mRNAs containing premature termination codons (PTCs)--nonsense-mediated mRNA decay (NMD) pathway. In yeast Saccharomyces cerevisiae the activity of this pathway depends on the recognition of the PTC by the translational machinery and interaction of translation termination factors eRF1 (Sup45) and eRF3 (Sup35) with Upfl, Upf2 and Upf3 proteins. Previously we have shown that decreasing of eRF1 amount causes an impairment of NMD.

[The origin of novel proteins by gene duplication: what is common in evolution of the color-sensitive pigment proteins and translation termination factors].

The review is discussing a role of duplications in evolution, including events from genes to genomes duplications. The important role of duplications is their participation in the block-modular reorganizations leading to a combination of fragments from various genes. Examples of gene duplications leading to occurrence of proteins with divergent functions are shown.

[Evaluation of the gene encoding translation termination factor eRF3 as a possible phylogenetic marker].

We have tested if a part of nuclear gene GSPT2 encoding N and M domains of translation termination factor eRF3b could be applied as a new molecular marker, using order Rodentia as a model group. The proposed fragment cannot be used as a phylogenetic marker at intrageneric level because of low variability within families and impossibility to resolve relationships in family Cricetidae. However, this part of GSPT2 gene allows to divide higher taxa reliably.

[Viable nonsense mutants for the SUP45 gene in the yeast Saccharomyces cerevisiae are lethal at increased temperature].

Nonlethal nonsense mutations obtained earlier in the essential gene SUP45 encoding the translation termination eRFI factor in the yeast Saccharomyces cerevisiae were further characterized. Strains carrying these mutations retain the viability, since the full-length eRF1 protein is present in these strains, although in decreased amounts as compared to wild-type cells, together with a truncated eRF1. All nonsense mutations are likely to be located in a weak termination context, because a change in the stop codon UGAA (in the case of mutation sup45-107) to UAGA (sup45-107.

[Conservation of the MC domains in eukaryotic termination factor eRF3].

Eukaryotic translation termination employs two protein factors, eRF1 and eRF3. Proteins of the eRF3 family each consist of three domains. The N and M domains vary in different species, while the C domains are highly homologous.

[Yeast prions, mammalian amyloidoses, and the problem of proteomic networks].

Prion proteins are infective amyloids and cause several neurodegenerative diseases in humans and animals. In yeasts, prions are expressed as cytoplasmic heritable determinants of a protein nature. Yeast prion [PSI], which results from a conformational rearrangement and oligomerization of translation termination factor eRF3, is used as an example to consider the structural--functional relationships in a potentially prion molecule, specifics of its evolution, and interactions with other prions, which form so-called prion networks.

[Increased tRNA concentration in yeast containing mutant termination translation factors eRF1 and eRF3].

Earlier we have characterized strains bearing mutations in essential genes SUP45 and SUP35 of yeast S. cerevisiae, encoding translation termination factors eRF1 and eRF3 respectively. In the present work nonsense-mutants on genes SUP45 and SUP35 have been compared by a level of eight tRNA: tRNATyr, tRNAGln, tRNATrp, tRNALeu and tRNAArg (previously described as potentially suppressor tRNA), and also tRNAPro, tRNAHis and tRNAGly.

[Characterization of missense mutations in the SUP45 gene of Saccharomyces cerevisiae encoding translation termination factor eRF1].

Collection of missense mutations in the SUP45 gene of Saccharomyces cerevisiae encoding translation termination factor eRF1 has been obtained by different approaches. It has been shown that most of isolated mutations cause amino acid substitutions in the N-terminal part of eRF1 and do not decrease the eRF1 amount. Most of mutations studied do not abolish eRF1-eRF3 interaction.

[Enteral correction of homeostasis in acute pancreatitis].

The experiments showed that heart and liver functional abnormalities will take place even before changes of blood amylase is occurred. It was shown that Dalargin in a dose of 50 micrograms/kg will stimulate the intestinal absorption.

[Effects of caffeine on occupationally important functions of locomotive operators].

The study covered effects of Caffeine on simple and integral reactions of locomotive drivers. A total of 224 individuals was polled. Caffeine appeared to stimulate significant occupational functions of the drivers in first hours and subsequently hamper them by 2nd--4th hours.

[Microanalytical methods: latex agglutination and immunoenzyme analysis in the diagnosis of meningococcal infection].

Modified polystyrene latexes with high adsorption capacity, comparable to that of latexes produced by Difco Laboratories (USA), have been developed in the USSR. Diagnostic latex preparations for the detection of meningococci of serogroups A, C, Y and Haemophilus influenza, type b, prepared on the basis of these new latexes, have shown high specificity and sensitivity in experimental and clinical tests. The latex preparations for the detection of serogroup B meningococci requires further improvement.

[Increased specificity of immunoenzyme analysis for diagnosing meningococcal infection].

The ELISA test system for the detection of polysaccharide antigens of meningococci, groups A and C, on the basis of the neutralization of specific antibodies has been developed. The specificity of this reaction is determined by the chemically pure preparations of group A and C meningococcal polysaccharides. The sensitivity of this test system based on the neutralization of antibodies is not inferior to that of ELISA with the use of double antiserum.

[Etiological diagnosis of suppurative bacterial meningitis today].

As the result of laboratory examination of 2165 patients with virulent bacterial meningitides, including cases of meningococcal infection, the etiological diagnosis was confirmed in 1407 patients (65.0%), the number of cases confirmed by the laboratory examination being significantly greater among adults than among children: 67.5 +/- 1.

[Immunoenzyme method in the diagnosis of meningococcal infections].

The materials on the development and use of the test system, based on the enzyme-linked immunosorbent assay (ELISA) and intended for the detection of specific group A and C meningococcal polysaccharides and type b Haemophilus influenzae polysaccharide in the spinal fluid of patients, are presented. In this work commercial preparations manufactured in the USSR were used, and all parameters of the assay were developed on the basis of these preparations. The study was made on the samples of spinal fluid from 410 patients; of these, 203 had meningococcal infection, 57 had purulent bacterial meningitides and 150 had other diseases (acute respiratory diseases, influenza, etc.

[Surface antigen structure of Neisseria meningitidis. I. The isolation of a serotypic antigenic complex of N. meningitidis strain B16B6 by direct detergent treatment and its immunochemical characteristics].

The method for obtaining a serotyping antigenic complex from N. meningitidis B16B6 by their direct treatment with the mixture of detergents (0.5% sodium desoxycholate and 0,5% cholic acid in the proportion 1 : 1) in 0.