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Biomedical subjects

S L Rybalko

Publications and source records attributed to S L Rybalko.

At least 19 recordsLinked to original sources
PubMed2001

Virus-inhibitory effect of a yeast RNA-tilorone molecular complex in cell cultures.

The virus-inhibitory activity of a molecular complex (MC) of tilorone and yeast RNA was studied in vitro on three virus-cell systems: vesicular stomatitis virus (VSV) - murine fibroblast L929 cells, Venezuelan equine encephalittis virus (VEEV) - swine embryo kidney (SEK) cells and encephalomyocarditis virus (EMCV) - established piglet testicular (EPT) cells. In all these systems the MC exerted an antiviral effect similar to that of polynucleotide interferon (IFN) inducers such as poly(I)-poly(C), larifan and ridostin. The antiviral effect of the MC was similar when the compound was applied before or after virus adsorption to cells. The MC may be regarded as a perspective antiviral agent of common use.

Cells, Cultured↗
PubMed2000

Biological active acridine derivatives. Part 4: Synthesis and antiviral activity of some bis-acridinylated diamides.

Nine bis-acridine derivatives have been synthesized in search of structures with antiviral properties. Synthesis of target compounds was provided by a standard peptide-like coupling procedure using aliphatic diamines and protected amino acids following protective group removing and acridinylation by means of 9-methoxyacridine. Two out of nine compounds tested demonstrate high protective activity of Vero cells against HSV infection. Antiviral activity was observed only for compounds containing a pentamethylene fragment as a linker. The alanyl-containing derivative was less active than those containing valyl- and phenylalanyl. Most of synthesized compounds were less toxic than N,N'-bis-(acridinyl) hexamethylenediamine.

Acridines↗
PubMed1999

[Comparative cytotoxic characteristics of the interferon-inducing yeast RNA-tilorone complex].

Cytotoxicity of the yeast RNA-tilorona molecular complex (MC) with interferonogenic properties and its influence on the DNA replicative synthesis were studied in experiments with human lymphocytes and 3 cell lines. It was shown that the MC doses of 25, 100 and 250 micrograms/ml were absolutely nontoxic for all the cell lines. The main parameters of the MC toxicity based on the cell viability were calculated. The parameters were found to correlate in the order of their magnitude with those relating to interferonogens of the polynucleotide nature. Within the dose ranges of 10 to 100 micrograms/ml the MC had a stimulating effect on replicative processes in the cells. It was concluded that the use of the MC as an inductor in large-scale manufacture of human and animal interferons of type 1 was promising.

Animals↗
PubMed1998

The effect of trimeric 2',5'-oligoadenylic acid and its epoxy-derivative on human immunodeficiency virus (HIV-1) reproduction and retroviruses reverse transcriptase activity.

The effect of trimeric 2',5'-oligoadenylic acid (2',5' A3) and its epoxy-derivative (2',5'-A2 (RAA) on human immunodeficiency virus (HIV-1) reproduction was studied. An HIV-1 infectivity titer decrease was shown on the model of limphoblastoid cells when the substances under study were used. The interferonogenic effect of both substances was discovered. 2',5'-A2 (RAA) inhibited the activity of retrovirus reverse transcriptase (a C-type).

Adenine Nucleotides↗
PubMed1994

[The combined treatment with prednisolone and recombinant alpha 2-interferon of patients with chronic hepatitis B: the factors influencing the immune response].

The study included 39 patients with chronic HBeAg and DNA HBV-positive hepatitis B. 18 patients received combined therapy with prednisolone and recombinant interferon. Pretreatment investigations involved assessment of the basic virus replication by HBeAg, IgM anti-HBc, RPSHA titers, of DNA HBV concentration, alanine aminotransferase activity. The serum was examined for antibodies to alpha 2-interferon using enzyme immunoassay. The treatment resulted in disappearance of HBeAg in 70.6% of the examinees, DNA HBV in 66.6% of them. AlAT activity returned to normal in 58.8% of the patients. HBeAg and HBsAg were not registered in 5.6% of the patients. In 2 out of 4 nonresponders antibodies to alpha 2-interferon were absent. It is shown serologically that patients with initially low HBeAg, DNA HBV, high activity of AlAT, high titers IgM anti-HBc, no antibodies to alpha 2-interferon have the most favourable prognosis of the hepatitis.

Adult↗
PubMed1990

[The use of an immunoenzyme method for detecting enteroviruses].

It was established as a result of these investigations that the immunoenzymatic method may be used for detection of enteroviruses both in materials from human subjects and from objects of the environment. It is shown that the immunoenzymatic method has advantages as compared with the virological.

Antigens, Viral↗
PubMed1987

[Early detection and rapid identification of Streptococcus pneumoniae and Haemophilus influenzae in acute pneumonias].

The comparative study of the diagnostic value of the enzyme immunoassay (EIA), indirect immunofluorescence (IF) and countercurrent immunoelectrophoresis (CIE) was made. The serological identification of the isolated and reference pneumococci (19) and H. influenzae (38) strains revealed the possibility of using all three microanalytical methods for this purpose. The study of pneumococcal and H. influenzae antigens in native sputum obtained from 74 patients with acute pneumonia showed that EIA and indirect IF were highly sensitive, their sensitivity considerably exceeding that of the bacteriological analysis. Pneumococcal antigens were detected in 66.2% of patients by EIA and in 54.0% of patients by indirect IF, while H. influenzae antigens were detected in 58.1% of patients by EIA and in 67.6% of patients by indirect IF. The sensitivity of CIE proved to be considerably lower; in the detection of pneumococcal antigens it was level with the sensitivity of the bacteriological analysis (23.0%) and H. influenzae antigens could be detected only in 27.0% of patients.

Acute Disease↗
PubMed1986

[Dynamics of Shigella interaction with the epithelium in the infection process].

The study of the adhesion of Shigella flexneri to intestinal mucosal explants from human postabortion fetuses, used as an experimental model, has revealed that the process of interaction between the infective agent and the epithelium develops in accordance with Langmuir's equation of the adsorption isotherm. The specific biological feature of the adhesive interaction between bacteria and the mucous membrane is the fact that the effective adhesion of microbes is possible only in case of their high concentration on the surface of the mucous membrane. In case of their low concentration in the parietal layer no microbial adhesion is observed, whereas epithelial villi infected with shigellae and fixed to the mucous membrane of the explant produce a high parietal concentration of the infective agents, which leads to the increase of adhesion by more than two orders.

Adhesiveness↗
PubMedDate not supplied

[The toxicity and interferon-inducing activity of the lipopolysaccharides of Cytophaga sp. (strains 81 and 92)].

The experiments on mice and cell culture of a kidney of green monkey Vero have shown that lipopolysaccharides (LPS) of the studied strains 81 and 92 of Cytophaga sp. were nontoxic. They were less active as compared to LPS of other Gram-negative bacteria as to interferon-inducing activity. A comparative study of initial and dephosphorylated LPS has shown that phosphate groups were not responsible for the interferon-inducing activity of LPS of Cytophaga genus representatives.

Animals↗
PubMedDate not supplied

[Construction of the immunoenzyme test system "IFA-AtEBV-Strip" for detecting antibodies of the Epstein-Barr virus].

The first home immunoenzyme test-system for finding antibodies to the Epstein-Barr virus (EBV) has been created. The test-system laboratory prototype was called "IFA-AtEBV-strip". Production technology has been developed for specific components of immunoenzyme test system and all the analysis stage conditions have been optimized: the antigen sorption on plates, its interaction with the studied serum, finding out of the formed immune complex. The test system "IFA-AtEBV-strip" sensitivity made up 96%, specificity--100%.

Antibodies, Viral↗
PubMedDate not supplied

[Interferon induction by lacticacid bacteria in vitro and in vivo experiments].

Interferonogenic acitivity of lacticacid bacteria was studied in experiments in vitro and in vivo. It have been shown, that interferon induction depends both on strain species and on culture medium used for lactobacteria harvesting. Streptococcus thermophilus induces interferon more actively in leucocytes (in vitro)--1280 AU/ml on the bines broth medium, and less actively--320 AU/ml on fermented corn medium. Interferon induction in human leucocytes was not registered in case of L. plantarum 200 strain. In vivo experiments show that E. faecium strain and strain mixture of streptococcus termophilus are active interferon inductors. Induced interferon is recognized as alpha- and gamma-interferon, with domination of alpha-interferon.

Cells, Cultured↗
PubMedDate not supplied

[Glycopolymers of Clavibacter michiganense and Pseudomonas solanacearum--interferon inducers].

A polysaccharide, being an active inductor of gamma-interferon, has been found among glycopolymers of Clavibacter michiganense. Lipopolysaccharide of Pseudomonas solanacearum is shown to display an interferonogenic activity which is analogous to that of the classical interferon inductor, lipopolysaccharide of Escherichia coli O55: B5. Besides lipid A, core oligosaccharide also contributes much to the interferonogenic activity of P. solanacearum lipopolysaccharide.

Cells, Cultured↗
PubMedDate not supplied

[Indication of the influenza virus in clinical samples using immunoenzyme and lanthanide immunofluorescence analyses].

A comparative study of the potentials of enzyme-immunoassay (EIA) and lanthanide immunofluorescent assay (LIFA) for influenza virus detection in nasopharyngeal aspirates and nasopharyngeal washings was carried out. Monospecific and polyclonal antisera to hemagglutinin polyclonal antisera to matrix protein as well as polyclonal and monoclonal antisera to nucleoprotein were used. The nasopharyngeal aspirates were shown to contain virus-specific antigens in the amounts sufficient for influenza virus detection with polyclonal and monoclonal antibodies. There was a good correlation between chromophore results by EIA and fluorescence level in LIFA. The sensitivity of the test systems used (EIA and LIFA) was shown to be insufficient for the detection of virus-specific material in the nasopharyngeal washings. Besides, there was no correlation between the results obtained by different test systems. It was concluded that nasopharyngeal aspirates should be collected for rapid influenza diagnosis by EIA and LIFA.

Antibodies, Monoclonal↗