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Biomedical subjects

A V Karpov

Publications and source records attributed to A V Karpov.

At least 19 recordsLinked to original sources
PubMed2006

A complex interferon inducer potentiates the functional macrophage activity during Staphylococcal infection.

The antibacterial effect of a new type I interferon inducer, an yeast RNA-tilorone molecular complex (MC), was studied using a model of staphylococcal infection. The MC taken in experimental doses being optimal interferon-inducing ones accelerates the Staphylococcus aureus elimination from mice organisms accompanied by increased functional ability (phagocytosis and bactericide activity) of peritoneal macrophages. The conclusion is that the MC antibacterial activity detected is mediated by its interferon-inducing properties.

Animals↗
PubMed2001

Endogenous and exogenous interferons in HIV-infection.

The interferons (IFNs) belong to the body's natural defensive response mechanisms directed against virus infections including also the human immunodeficiency virus (HIV) infection. This review discusses the current knowledge concerning the role of IFNs types I and II during the HIV infection. The author analyzes the HIV-driven process of endogenous IFNs induction in different cell types as well as the development of unusual acid-labile IFN following the HIV infection, its nature and clinical significance. Possible action mechanisms of different exogenous IFN types against the HIV-infection are reviewed taking into consideration the stages of HIV replication accompanied by these mechanisms of action and describing both positive and negative roles of IFNs during this disease. The author discusses also some well-known IFN-inducible antiviral pathways participating in the anti-HIV mechanisms and enzymes realizing antiviral action (PKR, 2'5'-OAS, iNOS, IDO, Mx and 9-27 proteins). A problem of HIV defense against the anti-HIV IFN action as well as some aspects of HIV-accelerating IFN effects are also examined in detail.

Anti-HIV Agents↗
PubMed2001

Description and identification of difficulties arising from the application of a cleaning process in operating conditions for the treatment of components used on liquid metal fast reactors (LMFR). A technical designed approach to avoid these situations.

The cleaning process is one of the major maintenance operation for liquid metal fast reactors (LMFRs), both in operation and in their decommissioning stage. Russian and French cleaning processes are briefly described, including problems which have arisen during the processes. It appears that the cause of these problems is always connected to bad draining of the component, resulting in a vigorous reaction between vapour or liquid water and the bulk of sodium. From this discussion, the paper makes major recommendations for the efficient and safe cleaning of sodium wetted components, and proposes several processes which should be developed in order to deal with difficult situations, for example the removal of large amounts of undrainable sodium.

Chemical Precipitation↗
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

[Economic expediency and medical efficiency of methods for active detection of tuberculosis].

The data collected in the Novgorod region show a significant deterioration of the tuberculosis epidemiological situation. The economic and medical efficiencies of the current methods of active detection of tuberculosis are comparatively assessed. There is evidence for high effectiveness of enzyme immunoassay in detection of blood tuberculosis antibodies. A new concept of a differentiation system for of organization of goal-oriented prophylactic population surveys for tuberculosis.

Antibodies, Bacterial↗
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↗
PubMed1999

Hydrolysis of tripolyphosphate by purified exopolyphosphatase from Saccharomyces cerevisiae cytosol: kinetic model.

The kinetics of hydrolysis of tripolyphosphate by purified exopolyphosphatase from Saccharomyces cerevisiae cytosol has been studied in the presence of Mg2+. Two kinetic models suggesting the formation of complexes of tripolyphosphate and the enzyme with Mg2+ are compared. Both models suggest that only enzyme--substrate complexes containing Mg2+ and tripolyphosphate simultaneously are able to hydrolyze the tripolyphosphate. The first model suggests that the enzyme is able to bind to Mg2+ independently from substrate binding. The second model does not consider this possibility, but suggests that both complexes containing tripolyphosphate and Mg2+ in proportion 1:1 and 1:2 can serve as the reaction substrates. The description of the experimental data by both models is essentially the same. The complex containing tripolyphosphate and Mg2+ in proportion 1:1 is optimal for the enzyme activity, the complex containing tripolyphosphate and Mg2+ in proportion 1:2 being hydrolyzed at a lower rate.

Acid Anhydride Hydrolases↗
PubMed1998

[Use of blast transformation test with different tuberculin dilutions to evaluate functional activity and directivity vector of T-cell activation in patients with tuberculosis during chemotherapy].

The lymphocyte blast transformation test (LBTT) with three tuberculin dilutions was used to examine 190 patients with varying pulmonary tuberculosis activity, of them 63 patients received chemotherapy. According to the blast formation in the patients' cultured peripheral blood cells by three tuberculin dilutions, a correlation was found between the clinical manifestations of the process and the functional activity of T lymphocytes. Thus, the greatest percentage (500 TU) of blasts in LBTT per mean PPD dose was detectable in patients with low LBTT results by three tuberculin dilutions with positive dynamics during chemotherapy. With further positive dynamics, the proportion of blasts in the cultured peripheral blood cells was highest per high PPD doses (5000 TU). On the contrary, patients with progressive tuberculosis displayed a oppositely directed phasic pattern.

Antigens, Bacterial↗
PubMed1997

Competition of plasmid-bearing Pseudomonas putida strains catabolizing naphthalene via various pathways in chemostat culture.

Plasmid-carrying Pseudomonas putida strains degrade naphthalene through different biochemical pathways. The influence of various combinations of host bacteria and plasmids on growth characteristics and competitiveness of P. putida strains was studied in chemostat culture at a low dilution rate (D = 0.05 h-1) with naphthalene as the sole source of carbon and energy. Under naphthalene limitation, the plasmid-bearing strains degrading naphthalene that use catechol 1,2-dioxygenase for catechol oxidation (ortho pathway), were the most competitive. The strains bearing plasmids that control naphthalene catabolism via catechol 2,3-dioxygenase (meta pathway), were less competitive. Under these conditions the strain carrying plasmid pBS4, which encodes for naphthalene catabolism via gentisic acid, was the least competitive.

Bacterial Proteins↗
PubMed1996

[A standard immunoenzyme test system for detecting antibodies to the causative agent of tuberculosis: the means for its utilization in tuberculosis control work].

A new standard immunodiagnosticum made in Russia has been tested as a main method of total screening of population sample (32587 citizens of the Novgorod Region). The resultant tuberculosis detection rate was not inferior to x-ray findings. More than one-third of the diagnosed cases had bronchial tuberculosis hardly detectable by x-rays. A new three-stage scheme of early diagnosis of tuberculosis has been developed.

Antibodies, Bacterial↗
PubMed1995

[The interferonogenic properties of yeast RNA-tilorone complexes in a cell culture].

The use of molecular complexes of yeast RNA with thyloron as inductors of type I interferons (alpha/beta-interferons) in the culture of cells L929 is described. It was shown that the complexes induced the interferon synthesis in the cells at the level comparable to that of the standard inductors of the polyribonucleotide nature i.e. larifan and poly(I)-poly(C). In the experimental doses the complexes proved to be nontoxic. It was concluded that the use of the yeast RNA and thyloron complexes as inductors in large-scale production of type I interferons was promising.

Animals↗
PubMed1993

[Nucleotide sequence of phospholipase C and sphingomyelinase genes from Bacillus cereus BKM-B164].

A BamHI-EcoRV DNA fragment, containing tandemly arranged genes for the Bacillus cereus VKM-B164 phosphatidylcholine-specific phospholipase C and sphingomyelinase, has been cloned and sequenced in pUC19 plasmid (EMBL accession No X64141). The obtained gene sequences have been compared with those the B. cereus strains SE-1, IAM-1208 and GP-4 reported previously. Both phospholipase C and sphingomyelinase gene sequences of the VKM-B164 strain were found to be identical to those of the strain SE-1 and to differ from the sequences of GP-4 and IAM-1208 strains, containing another version of the gene sequences.

Amino Acid Sequence↗
PubMed1992

[Possibilities of restoration of the regional lymphatic channel by the use of sorbents in the treatment of experimental generalized purulent peritonitis].

Regional lymphatic bed in local application of mineral sorbent SUMS-2p in 80 white noninbred rats with experimental generalized purulent peritonitis is studied with the use of indirect intravital lympho-roentgenography. The correlation between lympho-dynamics and generalized purulent peritonitis stage was observed. It is shown that the peritoneo-sorption with the mineral sorbent SUMS-2p led to early restoration of lympho-drainage.

Animals↗
PubMed1992

[Changes in the lymphatic system in the crush syndrome].

In vivo indirect electrolymphoroentgenography was conducted to study the reaction of lymphatics during prolonged compression syndrome (PCS). The studies were made on white rats, Wistar-line, males. It was found out that the early period of clinical course of PCS was characterized by lymphostasis. The intermediate period of PCS corresponds to the stage of the collateral lymphokinesis. At the edge of intermediate and late period of PCS the electrolymphoroentgenogram shows the removal of lymphostasis and recovery of main lymphokinesis.

Animals↗