[Directed reconstruction of the influenza virus hemagglutinin gene].

A new approach to create chimeric genes by directed exchange of oligonucleotide fragments was developed. By oligonucleotide-directed mutagenesis a few deletion mutants of the influenza virus hemagglutinin (HA) gene were obtained. These variants of HA gene contain unique restriction sites in DNA regions coding for the A and B epitopes of the HA molecule.

[Study of the mechanism of mutagenesis directed by phosphotriester analogs of oligonucleotides. The role of repair in mutagenesis].

The mutation system has been suggested in an effort to test insertion and deletion mutants by changing the Lac-phenotype of bacterial colonies transformed by mutant DNA. This system also makes possible to determine heterozygotes and homozygotes among the mutants. The yield of mutants in shown to depend on the structure of the DNA heteroduplex region.

[Mutagenesis directed by phosphotriester analogs of oligonucleotides: a way to site-specific mutagenesis in vivo].

A new approach is proposed to obtain the directed mutations in the gene under study. The technique is based on using alkylphosphotriester analogues of oligodeoxyribonucleotides as site-specific mutagens. The deletion C in lacZ' gene of bacteriophage M13mpB was obtained by cotransfection of Escherichia coli cells with a mix of DNA and phosphotriester analogues of oligonucleotides.

[Mutagenic properties of phosphotriester analogs of oligodeoxyribonucleotides].

The high effectivity of using phosphotriester analogs of oligonucleotides for aimed mutagenesis in vitro and in vivo was shown. A general scheme, describing the mutagenic effects of phosphotriester analogs of oligonucleotides and their natural homologs, was derived by analysis of data on the structures of the obtained mutants. This scheme can serve as a foundation for selecting the structure of effective agents for aimed mutagenesis.

[Primary structure of the mutant genes of human leukocyte interferon alpha2].

Nucleotide sequences of 10 mutant genes of human leukocyte interferon alpha 2 (IFN) with the use of 4 oligonucleotide primers containing ethyl substituents at phosphate groups were determined. To design primer sequences, an approach based on the local similarity profile of the IFN gene and M13mp7 vector DNA is described.

[Expression in Escherichia coli of the human leukocyte interferon alpha2 gene fused with N-terminal fragment of beta-galactosidase].

Genes for leucocyte interferon and alpha-donor of galactosidase were fused by deletion mutagenesis or by site-directed mutagenesis. In both cases the fused protein was expressed. The protein having an antiviral activity of leucocyte interferon was easily detected in bacteria and solutions by the reaction of beta-galactosidase alpha-complementation and retained the antigenic determinants of interferon and beta-galactosidase.

[DNA carrying aliphatic amino groups and the use of its fluorescent derivative as a probe in molecular hybridization].

A two-step method of labelling DNA through aliphatic amino groups with various reporter molecules has been developed. The method is based on reaction of cytosine-residues of polynucleotide chain with 4-aminooxybutylamine; the latter's synthesis is described. DNA modified on this way with fluorescein isothiocyanate functions a probe in molecular hybridisation.

[Site-localized mutagenesis directed by phosphotriester analogs of oligonucleotides].

17- and 20-mer oligodeoxyribonucleotides and their analogues, containing one to four phosphate groups esterified with ethyl alcohol in different positions of oligonucleotide chain, were synthesized by modified triester method. Ethylated di- and trinucleotide blocks were prepared by transesterification method from chlorophenyl derivatives. The structures of the oligonucleotides were confirmed by Maxam-Gilbert sequencing method.

[Mutagenesis directed by phosphotriester analogs of oligonucleotides].

20-mer oligodeoxyribonucleotides d-ACGACGG (R') CCAG (R'') TGATCCGTA, where R' = R'' = H (20), F' = Et, R'' = H (20-Et), or R' = R'' = Et (20-Et2) were synthesized by modified triester method. Ethylated dinucleotide blocks were prepared by transesterification method from chlorophenyl derivatives. Structures of oligonucleotides were confirmed by Maxam - Gilbert method.

[Systemic hemodynamics and regional microcirculation in diffuse peritonitis].

A complex study of the central and peripheral hemocirculation in 134 patients and direct control of the microcirculation bed by the method of contact microscopy in 15 experiments in dogs were used in order to study the character of disturbances of microcirculation depending on the phase of diffuse peritonitis. It was established that a reactive of peritonitis is characterized by an active spasm of microvessels changed by their paralytic dilatation followed by stasis, aggregation of formed elements, edema and infiltration of tissues.

[Complexes of nonionic triether analogs of oligonucleotides with polynucleotides].

Alkyl triester analogues of oligodeoxynucleotides were synthesized: [Tp(CH3)]8T(Ac), [Tp(C2H5)]8T, [dGp(C2H5)]2G, [dAp(C2H5)]2A. Their binding to complementary polyribo-and polydeoxyribonucleotides was studied by UV-spectroscopy and gel-filtration. The DNA complexes of analogues were shown to be more thermostable than the RNA ones independent on the nucleic base nature and alkyl residue size of the analogue used.

[Character of organ volume vessels during pressor reflexes].

In acute experiments on cats, responses of the resistance and capacity vessels of small intestine, spleen, kidneys, and m. gastrocnemius were studied during pressor sinocarotid reflex and electrical stimulation of the sciatic and brachial afferents. It was shown that, against the background of constrictory responses of the resistance vessels in these organs, both the constrictory and the dilatory responses of the capicitance vessels could occur or not.

[Changes in the diameter of organ arteriovenous anastomoses during pressor reflexes].

In acute experiments on cats, the diameter changes of the arterio-venous anastomoses in a number of vascular zones and their shunting coefficient were studied under the pressor reflexes; the method of injections of the microspheres was used. In these experiments the shunting capacity of the arterio-venous anastomoses was shown to be decreased in the small intestine, the spleen, the kidney and the gastrocnemius muscle under the pressor synocarotid reflex and the electrical stimulation of the somatic afferents.