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Biomedical subjects

T G Orlova

Publications and source records attributed to T G Orlova.

At least 19 recordsLinked to original sources
PubMed1992

[Effect of mytilane, a bioglycan from the mussel Crenomytilus grayanus, on the course and outcome of experimental flu infection].

Materials characterizing the antiviral activity of Mytilane, manifested by the protection of 50-60% of mice infected with the lethal dose of influenza virus and by a decrease in the severity of pathological changes in the lungs of mice, are presented. The inhibiting activity of Mytilane with respect to the reproduction of influenza virus in vivo and in vitro under experimental conditions is demonstrated.

Adjuvants, Immunologic↗
PubMed1991

[Use of alpha interferon preparations in acute lymphoblastic leukemia in children during remission].

The Soviet alpha-interferon drugs (human leukocytic interferon, reaferon) were used in the program of the treatment of children with acute lymphoblastic leukemia (during remission). The treatment was found to be more effective with an increase of its duration, relapse-free course of the disease (69.4-82.3%) and survival (70.1-93.1%) of patients with an unfavourable disease prognosis (over 5 years).

Adolescent↗
PubMed1990

Production of alpha-interferon by human leukocytes.

We examined the capacity of human leukocytes to produce alpha-interferon subtypes following viral induction. It was shown that the beta-propiolactone inactivated viral inductor stimulated the production of a complete set of native alpha-interferon subtypes. Acid treatment of native interferon at pH 2.0 inactivated the acid-labile portion of alpha-interferon. Its exposure to 37 degrees C for 5 days and repeated acid treatment at pH 2.0 resulted in additional inactivation of some interferon pool fractions. The acid-labile subtypes of human alpha-interferon were formed in a nonadherent mononuclear cell fraction.

Humans↗
PubMed1989

[Effect of splenic cells sensitized with staphylococcal enterotoxin A on the metastasis of Lewis lung carcinoma in mice].

The effect of intact mouse spleen cells sensitized in vitro with staphylococcus aureus enterotoxin A (SEA) on spreading of mouse Lewis carcinoma was studied. A significant decrease in a number of metastases in the lungs and in the weight of the lungs was observed after multiple intrapulmonary inoculation of spleen cells treated with SEA for 6 hours. The effect was less marked after inoculation of the sensitized cells intraperitoneally or into the femoral muscle of the leg affected with the tumour. After multiple inoculations of the sensitized cells, the spleen cells of the treated animals develop the state of interferon hyporeactivity to SEA but not to PHA or NDV.

Animals↗
PubMed1989

[Interferon production by primary culture of human endothelial cells].

Endothelial cells of human umbilical vein are capable of producing interferon upon induction with Newcastle disease virus, influenza virus, and poly I: poly C, but not staphylococcal enterotoxin A. All the interferons produced belonged to the alpha-type. After treatment with influenza virus the endothelial cells produce two subtypes of alpha-interferon: acid-labile and acid-stable.

Cells, Cultured↗
PubMed1989

[Results of the use of human leukocytic interferon in the treatment program in acute lymphoblastic leukemia in children].

Soviet preparation of human leucocytic interferon (HLI) was injected to 112 children with acute lymphoblastic leukemia at different stages of the treatment program. The results obtained have evidenced that HLI produces a direct antitumor effect, intensifies the effectiveness of inductive chemotherapy and the treatment program leading to the prolongation of the remission period and survival of the patients, as well as induces activation of natural and antitumor resistance of the body.

Adolescent↗
PubMed1989

[Effect of staphylococcal enterotoxin A on the development of Lewis lung carcinoma in mice].

The effect of Staphylococcus aureus enterotoxin A (SEA) was studied for its effect on the development of the Lewis carcinoma in mice. It was shown that administration of SEA immediately after the appearance of the primary node in mice after transplantation of tumour cells led to insignificant inhibition of the node growth and a slight decrease of tumour metastasizing into the lungs. Inoculation of mice after the appearance of the primary node with 1/microgram of SEA 5 times a week significantly increased their survival rate. The lack of the marked effect of SEA appears to be associated with the disturbance of the immune interferon system functioning in tumour-bearing mice, since the production of serum interferon induced by SEA in mice with tumours was considerably lower than in the intact ones.

Animals↗
PubMed1988

Properties and content of cyclic nucleotide phosphodiesterase in photoreceptor outer segments of ground squirrel retina.

Cyclic GMP-specific phosphodiesterase (3',5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC 1.3.4.17) (PDE) is thought to be a key enzyme of the retinal-rod phototransduction cyclic nucleotide pathway. We attempted to investigate the properties and content of PDE in retinal-cone photoreceptors. The fractions obtained from cone-dominant ground squirrel retinas were analyzed for cone visual pigment content and PDE activity. The cone visual pigment content was estimated to be approx. 65 pmol per retina. The distribution of cone visual pigment coincided with that of the PDE activity through several steps of photoreceptor membrane purification by sucrose density gradient centrifugation. The ground squirrel retinal PDE was similar to the retinal-rod PDE by its kinetic properties, thermostability, sensitivity to tryptic activation, Stokes radius and pI values. The cone visual pigment enriched fractions contained the heat-stable trypsin-inactivated PDE inhibitor. Its functional properties seem to be similar to those of the retinal-rod PDE inhibitory subunit. The PDE content in ground squirrel retina was roughly estimated to be about five copies of enzyme per 100 cone visual pigment molecules. The obtained results indicated that the major portion of ground squirrel retinal cyclic GMP-specific PDE is the endogenous cone photoreceptor membrane enzyme and strongly supported the conception about the key role of PDE in cone phototransduction. The existence of essential differences between rod and cone systems rapidly returning cyclic GMP-specific amplification cascade components to the dark (or inactivated) states after photon absorption was suggested. If this suggestion is true, the well-known distinctions between response kinetics and light sensitivity of these two kinds of photoreceptor can be explained.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1988

[Effect of modulation of the production of interferon by L-929 cells treated with theophylline].

The specific inhibitor of cAMP phosphodiesterase theophylline has been shown to evoke in L929 cells 2.3-fold induction of 2-5A-synthetase activity and 3.5-fold superinduction of the same enzyme activity while acting in combination with actinomycin D. It has been shown also that temporal coincidence of 2-5A-synthetase induction with the active period of interferon production resulted in 8-16 times decrease in the level of interferon production. The result was supported by the experiments of superinduced cells (containing the high stable level of 2-5A-synthetase) fusion with monolayer of poly(I).poly(C)-induced L929 cells (taken at the start of interferon production). In this case the production of interferon was dramatically decreased in comparison with the control. Possible role of 2-5A-synthetase in regulation of interferon production is discussed.

2',5'-Oligoadenylate Synthetase↗
PubMed1987

The influence of high temperature on human cells in culture, their sensitivity to viruses and their interferon-producing capacity.

The influence of extremely high temperatures on the course of virus infection in vitro was studied. It has been shown that exposure of human cells (continuous cell line of embryonal skin-muscle tissue, donor blood leukocytes) to 43 degrees C leads to a significant increase in their sensitivity to cytopathic action of the viruses tested. Noteworthy, the reproduction of these viruses under tested conditions did not differ from their reproduction in control cells. A dramatic inhibitory effect of high temperatures on the interferon-producing capacity of cells was observed.

Cell Line↗
PubMed1979

Comparative study on the anticellular and antiviral effects of interferon and the haemopoietic stem cell inhibition factor.

Pretreatment with crude interferon preparations obtained from suspension cultures of bone marrow, spleen and thymus cells or from mouse L-cell cultures or with mouse serum interferon preparations did not change the colony-forming activity of bone marrow cells on syngeneic transplantation to lethally irradiated mice. Preparations of L-cell culture interferon, dialysed and purified by carboxymethyl-Sephadex (G-25) column chromatography, showed an inhibitory effect on exogenous colony formation by bone marrow cells. The results suggested the presence in crude interferon preparations of a substance either inhibiting the anticellular effect of interferon or stimulating colony formation. The factor produced by thymus cells following their treatment with antilymphocyte serum inhibited colony formation by bone marrow cells and, unlike interferon, possessed no antiviral activity when tested in cell cultures.

Animals↗