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Biomedical subjects

A Z Pliusnin

Publications and source records attributed to A Z Pliusnin.

At least 19 recordsLinked to original sources
PubMed1991

[Nucleic acid molecular hybridization as a method for the laboratory diagnosis of influenza: its potentials and prospects].

Experiments carried out by the present moment in a number of laboratories indicate that the method of molecular hybridization (MH) has great diagnostic potential. Sufficient methodological mastery of the reaction of radioactively labeled DNA probes with RNA samples applied into a polymer membrane and good supply of commercially available materials make it possible to recommend this method for use in reference laboratories at specialized diagnostic centers. Hybridization should be used in combination with traditional virological and serological tests; the combined use of MH and the enzyme immunoassay for the determination of viral antigens permits the documentation of 90-98% of all cases of influenza A with sufficient rapidity. In the near future DNA probes for the diagnosis of influenza B and C are likely to appear. MH has rather good prospects for the analysis of experimental infection in laboratory animals, as well as for the study of the replication of influenza virus in all cultures. The prospects of the study of the processes of expression of individual genes seem to be particularly attractive. MH may play an important role as a tool for documenting vaccinal reaction, as well as for the study of the action of different chemical preparations in volunteers. And finally, the greatest expectations are linked with the use of MH for the search of inapparent (persistent, latent, etc.) forms of influenza virus infection both in experimental systems and in humans. Optimistic prospects of the studies in this field are based on high sensitivity of this method combined with its equally high specificity. An additional reserve for enhancing sensitivity is also present here due to the amplification of target molecules.

DNA Probes↗
PubMed1990

[The results of using the molecular hybridization of nucleic acids in the complex study of nasopharyngeal smears from patients with influenza and other acute respiratory diseases].

A complex study of samples obtained from patients with influenza and other acute respiratory diseases has revealed that the laboratory methods used in this study can be rated in the following order according to their sensitivity: isolation of the virus in chick embryos, analysis of seroconversions in the hemagglutination inhibition test, immunofluorescent determination of viral antigens, determination of viral antigens by enzyme immunoassay (EIA), detection of RNA-containing viral structures by means of molecular hybridization. From the point of view of the possibility of documenting influenza A in patients, the best results are achieved by the combination of molecular hybridization and EIA techniques: 90% and more of all cases. A rational scheme for the examination of samples obtained from patients with a view to epidemiological study, including both traditional and new rapid diagnostic methods, is proposed.

Acute Disease↗
PubMed1988

[Molecular hybridization of nucleic acids as a method for the laboratory diagnosis of influenza in model experiments on cell cultures and in research on nasopharyngeal smears obtained from patients].

DNA probes containing the nucleotide sequences of the conservative genes of influenza A virus (matrix, nucleoprotein and acidic polymerase genes) show their specificity with respect to the RNA of influenza A viruses in mammal tissue cell cultures (continuous spaniel kidney cell culture and primary calf kidney cell culture). The minimal amount of infected monolayer cells, permitting the detection of viral RNA, is 10(3). The results obtained in the study of nasopharyngeal washings make it possible to recommend the method of molecular hybridization for use in the epidemiological analysis in addition to virological and serological tests. The method of hybridization permits the detection of virus-specific RNA in the allantoic fluid of chick embryos in subculturing the materials under study even in those cases when hemagglutinating influenza virus cannot be isolated.

Animals↗
PubMed1985

[Initiation of RNA synthesis in isolated rat liver nuclei].

Isolated rat liver nuclei were incubated under conditions when RNA polymerase I or RNA polymerase II was preferentially active. It was shown that [gamma-32P] ATP and [gamma-32P] GTP were incorporated into phenol extractable, TCA-precipitable material. RNase, actinomycin D, heparin and, in the case of RNA-polymerase II, alpha-amanitine inhibited precursor incorporation. These data are interpreted as evidence in favour of the initiation of RNA synthesis in isolated rat liver nuclei.

Adenosine Triphosphate↗
PubMed1982

[Intercellular information transfer in the immunogenesis process. VIII. Analytical separation on agar and polyacrylamide gel of RNA fractions from the spleens of immunized and intact rats].

RNA isolated from the spleens of intact rats and from rats with immunized sheep red cells was fractionated through three steps: 1 - extraction from phenol nuclei at 50-55 degrees and 65-75 degrees C, 2 - calcium-phosphate chromatography, 3 - agar electrophoresis. Eight agar fractions were obtained of the spleens of immunized rats, an increased RNA content was manifested in at least three agar fractions: the first (4 S), the third (21 S) and the eighth (26 S) ones. The first and the eighth immune RNA fractions, as it was shown earlier, induce the synthesis of antibodies in the rat transplantable lymphosarcoma cell. The first agar fraction of nuclear RNA from the spleens of immunized and intact rats were additionally separated using PAAG electrophoresis. The 4 S agar RNA fraction appears to be rather heterogeneous. It contains 4 S, 4.5 S, 5 S, 5.8 S, U1, U2 and 8 SII fractions, which are low-molecular nuclear RNAs, the 4 S subfraction prevailing. It is suggested that the 4 S PAAG subfraction is most active in the synthesis of antibodies induced by the heterogeneous agar 4 S RNA.

Animals↗
PubMed1981

[Characteristics of the organization and expression of individual genes in eukaryotic cells].

The modern views on the organization and expression of single genes in eukaryotic cells, RNA structure and biosynthesis are reviewed. The problems of unstable gene localization ("mobile dispersed genetic elements") of some structural genes of cellular and viral origin are discussed. Peculiarities of transcription and processing of mRNA, pre-mRNA splicing are described. The information on the mechanisms of pre-mRNA splicing in normal and virus-infected eukaryotic cells, the role of low molecular nuclear RNA in the RNA splicing as signals for less than recognition greater than by specific nucleases and RNA synthetases are also regarded.

Animals↗
PubMed1980

[Study of influenza virus 4S RNA as a primer in reverse transcription].

The capacity of influenza virion 4S RNA for serving as low-molecular primer has been studied in RNA-directed DNA synthesis catalyzed in vitro by reverse transcriptase of avian myeloblastosis virus. 4S RNA purified by 8% polyacrylamide gel electrophoresis has been shown to stimulate the reverse transcription reaction in vitro and to be RNA primer. The stimulating activity of the primers has been shown to decrease as follows: 4S nuclear RNA of the rat liver oligo (dT)12-18 4S RNA of influenza virion. the template activity of high molecular weight genome RNA of influenza virion has been demonstrated to be negligible in vitro both in the presence of synthetic and natural primer.

Avian Myeloblastosis Virus↗
PubMed1980

[Hybridization properties of the 4S RNA of influenza virions].

Molecular hybridization of nucleic acids was used to show that 4S RNA from influenza virions cultivated in chick embryos is coded by the chick genome and represented by a group of cellular transport RNA. No complementary nucleotide sequences in 4S RNA molecules or genome RNA from influenza virions were found by means of the procedure used.

Animals↗
PubMed1980

[Low-molecular RNA in different rat liver and liver tumor cell fractions].

Low molecular weight nuclear RNAs (LMWN RNAs) from rat liver, Zajdela hepatoma and rat hepatoma induced by DENA have been studied. The changes in the relative content of nucleoplasmic U1 and U2 RNAs, nucleolus U3 RNA and chromatine 5S RNA have been discovered in both hepatomas. Whereas 8S1 and U3 RNA were found in polysomes from rat liver but not in those from Zajdela hepatoma.

Animals↗
PubMed1980

[Low molecular weight nuclear RNA of human gastric adenocarcinoma].

Low molecular weight nuclear RNAs (LMWN RNAs) isolated by thermal phenol fractionation from malignant tumor of the stomach and the mucous membrane of patients with gastric ulcer have been studied. There were found some differences in the relative content of U1 and U2 nucleoplasmic fractions as well as of loosely bound to a nucleolus U3 fraction of LMWN RNAs. The changes observed resemble those obtained earlier for experimental animal tumors.

Adenocarcinoma↗
PubMed1979

[Effects of low molecular weight nuclear RNAs on the activity of RNA polymerase II in isolated rat liver nuclei].

An attempt was made to elucidate the possible participation of low molecular weight nuclear RNAs in the transcription process. The parameters of the RNA synthesis cell-free system in isolated rat liver nuclei were studied for this purpose. Tissue homogenization in isotonic sucrose during isolation of the nuclei resulted in a loss of 4S nuclear RNA. The dependence of RNA synthesis on the salt concentration in the incubation medium is indicative of possible initiation of the RNA synthesis in this system. At salt concentration of 0.08 M 50-75% of incorporation is due to the activity of RNA polymerase II. Under these conditions the electrophoretically homogenous individual fractions of low molecular weight nuclear RNAs do not affect specifically the activity of RNA polymerase II. No evidence for the participation of low molecular weight nuclear RNAs in the mechanisms of heterogeneous nuclear RNA synthesis were obtained.

Animals↗
PubMed1979

[Low-molecular RNA subcellular localization and its binding strength with cellular structures].

Some fractions of low molecular weight (LMW) nuclear RNAs were shown to be present in the cytoplasm of rat liver cells. In addition to known 4S tRNA, 5S and 5,8S rRNAs U3 and 8S1 LMW nuclear RNAs, 8SII and 8SIII LMW RNAs have been detected in RNA preparations of free total and membrane-bound polysomes. The U3 and 8SI polysoma I RNAs seem to be associated with high molecular weight polysomal RNA. Using thermal phenol fractionation, that some LMW RNAs were shown to be slightly bound to the cellular structures whereas some others are bound more tightly. Considerable amounts of LMW RNAs are tightly bound to the chromosome-nucleolar apparatus. They can be extracted only at 85 degrees C. The data presented are discussed with regard to LMW nuclear and polysomal RNAs functions.

Animals↗
PubMed1979

[Subcellular localization of low-molecular RNA in the cells of chick embryos].

The subcellular distribution of chick embryo low molecular weight RNAs has been studied by the thermal phenol fractionation procedure. The major part of 8SII RNA, earlier discovered in some oncornaviruses and normal cells, was extracted by phenol at 4%. Our results thus give evidence of the cytoplasmic localization of this RNA. Another part of 8SII RNA, which has been extracted at 65 degrees, is thought to consist of newly synthesized molecules located in the nuclei. A similarity in subcellular distribution of low molecular weight RNAs from chick embryo and rat liver has been obtained, i. e. such a distribution may be of universal nature.

Animals↗
PubMed1975

[A change in the relative concentration of individual fractions of low molecular weight nuclear RNA in tumor tissues].

Low molecular weight nuclear RNAs (LMWN RNAs) of normal and neoplastic tissues: the rat liver and Zajdela hepatoma, mouse spleen and NK/Ly ascites tumor, as well as the cultures of normal chick embryo fibroblasts and of those transformed with Rous sarcoma virus were studied by electrophoresis in 8% and 15% polyacrylamide gels. As a result of the study no qualitative differences, i.e. differences in the number of LMWN RNA main fractions and their electrophoretic mobility were found. But there were revealed quantitative variations in the relative amount of definite fractions of these RNAs. An increase of the U3 RNA content in ascites tumors may be connected with an enhancement of the ribosomal RNA synthesis. Variations in the content of low molecular weight RNAs in oncogenic virus transformed cells may reflect an excessive synthesis of low molecular weight viral RNAs during the process of virus reproduction. The quantitative alterations observed seem to be of special value since LMWN RNAs are likely to perform regulatory functions.

Animals↗
PubMedDate not supplied

[The antigens and nucleotide sequences of influenza A and B viruses in the lymphocytes of human peripheral blood].

Markers of influenza A and B viruses (antigens of hemagglutinin and specific nucleotide sequences) were detected in lymphocyte preparations from normal subjects. The rate of detection of the antigens and specificity (type and subtype appurtenance) of the markers correlated with the influenza epidemic situation. Lower titers of antibodies to the virus whose antigens were present in lymphocytes were observed.

Adult↗
PubMedDate not supplied

[Effect of low-molecular nuclear RNA on RNA synthesis in isolated nuclei].

An attempt was made to elucidate possible participation of low molecular weight nuclear RNA's (LMWN RNA's) in the transcription process. For this purpose, we studied the effect of individual fractions of LMWN RNA's, isolated by polyacrylamide gel electrophoresis, on the endogenous RNA synthesis in isolated nuclei. We have found no influence of LMWN RNA's on the incorporation of labeled precursors in the acid-insoluble material under the conditions when RNA polymerase I is predominantly active. The results obtained thus indicate that LMWN RNA's do not participate in the regulation of 45S pre-rRNA synthesis and they do not belong to limiting factors in pre-rRNA synthesis.

Adenosine Monophosphate↗