[Monoclonal antibodies to 8-oxo-2'-deoxyguanosine (8-hydroxyguanosine). Characteristics and use for determining DNA damage by active forms of oxygen].

It has presently been established that the guanine base is one of the most sensitive and biologically significant target for the damaging action of active oxygen species on DNA, 7.8-dihydroxy-8-oxoguanine (8-oxoguanine, 8-hydroxyguanine) being the major degradation product and the most essential biomarker for DNA damage by active oxygen species. Murine monoclonal antibodies (MAbs) specifically recognizing 8-oxoguanine have been raised.

[Use of monoclonal antibodies for detecting Aujeszky's disease virus in culture media by an immunoenzyme method].

Three modifications of quantitative enzyme immunoassay (EIA) for assessment of Aujeszky's disease virus (ADV) in culture medium are compared, in which monoclonal antibodies (MAB) to ADV GH glycoprotein were used: nonconcurrent two-site "sandwich" EIA on the basis of two different MABs, indirect concurrent EIA, and direct concurrent EIA. MABs fit best of all for use in every of EIA modifications were selected. Conditions of the assays were optimized.

[The isolation and characteristics of monoclonal antibodies to the glycoprotein GII of Aujeszky's disease virus and their use for the epitopic mapping of GII].

A panel of 24 different monoclonal antibodies (MAB) to Aujeszky's disease virus (ADV) proteins was prepared. Seven MABs were directed to ADV glycoprotein GII (6 MABs to GIIc chain and 1 MAB to GIIb chain). GII epitope mapping with the resultant MABs was carried out.

[The detection of lipofuscin in a culture of hybridoma cells].

Lipofuscin granules (LG) are found in the cultured hybridoma cells producing monoclonal antibodies to phage. LG have been studied using light and electron microscopy. Luminescent spectra of LG clusters in hybridoma cells are presented.

[The demonstration of proliferating cells by using monoclonal antibodies to 5-bromo-2'-deoxyuridine in the peroxidase-antiperoxidase method].

Monoclonal antibodies (MAb) to the thymidine analog 5-bromo-2'-deoxyuridine (BrdUrd) and to horseradish peroxidase (HRPO) have been produced and characterized. On the basis of Mab to HRPO, complexes of the antibodies and HRPO (PAP-complexes) for immunochemical investigations are prepared. The possibility to identify proliferating cells in cultures of mouse myeloma Sp2/0 and mouse fibroblasts NIH 3T3 using Mab to BrdURd by the PAP-method is shown.

[Ultrastructural analysis of the action of centrophenoxine on retrovirus-transformed cells].

The ultrastructure of hybridoma cells cultured with 5.10(-4) centrophenoxine (CP) has been studied. It is shown that CP effects hybridomas and prevents retrovirus exocytosis.

[Antibody interaction with the amphotericin channel].

The monoclonal antibodies against asymmetric channel formed in the lipid bilayer of polyene antibiotic amphotericin B and cholesterol after addition of the antibiotic to the compartment from the cis side of the membrane were obtained. The effect of the antibodies on ion conductance of the channel depends on the distribution of cholesterol in the membrane. When cholesterol was present on both sides of the lipid bilayer, three antibody molecules bound to the channel from the trans side of the membrane, thus markedly increasing the lifetime of the open state of the channel.

[Regulation of the synthesis of total cellular proteins and monoclonal antibodies in a hybridoma cell culture].

A study was made of the regulation of total protein synthesis in cells of the mouse hybridoma producing monoclonal antibodies (McAb) against lambda phage, and in the course of hybridoma growth and at the change of fetal bovine serum (FBS) concentration. FBS strictly affected proliferation of hybridoma cells, the specific production of McAb per cell being unchanged. The rate of total cellular protein synthesis does depend on FBS concentration in the medium, whereas the rates of protein degradation and secretion do not.

[Purification of restriction endonuclease EcoRII using monoclonal antibodies].

Monoclonal antibodies against EcoRII endonuclease were obtained after immunization of two BALB/c mice with a homogeneous enzyme prepared by conventional methods. IgG from ascitic fluid was purified and coupled to CNBr-activated Sepharose 4B to give a specific column used to isolate EcoRII endonuclease. The isolated EcoRII endonuclease produced a single band during SDS gel electrophoresis.

[Monoclonal antibody metabolism during the growth of hybridoma cells].

Metabolism of monoclonal antibodies (MAb) during the growth of mouse hybridoma, producing MAb to phage lambda, has been studied. It was shown that the specific production of MAb decreased by 25-35% in the stationary phase of growth in comparison with the middle of the exponential growth phase, which was associated with the decrease in the rate of MAb synthesis. The secretion kinetics of MAb did not change during the growth of hybridoma cells.

[The use of monoclonal antibodies for purification of ribonuclease H from E. coli].

Monoclonal antibodies to E. coli ribonuclease H were obtained from two hybrid clones. Using the monoclonal antibodies two immunosorbents were synthesized for RNase H which have a slight difference in the capacity and do not differ in the conditions of antigen elution.

[Protein metabolism during the growth of hybridoma cells].

Protein metabolism during the growth of mouse hybridoma, producing monoclonal antibodies to phage lambda has been studied. The rate of protein accumulation Va at any time of growth was equal to that of protein synthesis Vs minus the degradative rate Vd and protein secretion rate Vsecr (Vn = Vs--Vd--Vsecr). Cellular protein metabolism was described in terms of the relationship 6.

[Effect of SH-reagents on Ca2+ level in lymphocyte cytoplasm].

The effect of SH-reagents on cytoplasmic free Ca2+ concentration [( Ca2+]i) in rat thymocytes and B lymphoma Raji cells has been studied by means of fluorescent Ca2+ indicator quin-2. N-ethylmaleimide and ethylmercurythiosalicylate have been found to induce a dose-dependent increase of Ca2+ concentration from about 100 nM in the control cells up to 1000 nM. The effect is weakened with a decrease of the external Ca2+ concentration and is not observed already with Ca2+ concentration in the medium less than 0.

[Hybridoma cultures using porcine serum not containing immunoglobulin and dialysis fractions].

The whole swine serum was treated with ammonium sulphate to precipitate immunoglobulins. The remained IgG was removed with the use of protein A-sepharose. The hybridoma cells producing monoclonal antibodies to lambda phage (class IgG) were cultured in Dalbecco's modified Eagle medium with addition of a 5% whole swine serum or of a treated unwhole one (final concentration of the protein being 3 mg/ml).

[DNA degradation during radiation death of cultured cells].

The method of flow cytofluorometry was used to study postirradiation changes in plasma membrane permeability and DNA content of the Burkitt's lymphoma cells (Raji line). At a dose of 10 Gy, the increase in membrane permeability preceded the appearance of cells with diminished DNA content. The synchronization of cells in phase G2 was associated with a virtually complete radiation arrest of mitoses.

[Swine serum increases hybridoma stability].

Three hybridoma cell lines producing monoclonal antibodies to lambda phage were cultured for 9 months in Dulbecco's modified Eagl's medium supplemented with 10% fetal calf serum or with 5% swine serum. Under these conditions all the clones had the same proliferation rates and maximum population densities. The cultuvation in the medium with swine serum enhanced the stability of hybridomas: all clones retained the ability to produce antibodies throughout the experiment; one of the clones examined enhanced the activity by 10(3)-10(4) times.

[Action of secondary radiation from 70-Gev protons on the cellular DNA of mammals].

A study was made of the effect of secondary radiation of 70 GeV protons on DNA of Chinese hamster cells. With a reference to fibroblast DNA, lymphoid cell DNA, and the lethal effect of radiation on the survival of Chinese hamster cells the RBE was 1.6-7.

[Advantages of using swine serum in culturing animal and human cell lines].

Using the culture of lymphoid human cells, mice myeloma cells and hybridoma (the latter was obtained by fusion of myeloma cells with those of mice spleen immunized with phage lambda), the fetal serum was shown to be surpassed in growth activity by that from adult swines. This fact is especially pronounced at small serum concentrations. When hybridoma cells were cultured there were no differences in titre of monoclonal antibodies specific to phage lambda with the use of both sera.

[Characteristics of culturing human lymphoid cells].

The growth characteristics of the human lymphoid cells were studied under various cultivation conditions. The cells were grown in flasks with different volumes of nutrient medium, in a spinner or in a specially constructed cultivator providing automatic maintenance of pH and gentle shaking of the suspension. It was found that the average time of the lymphoid cell generation decreases by 2-fold when the cells were grown in the cultivator.

[Effect of various substances on cultured mammalian cell growth].

The effect of different home industry materials on the growth of Chinese hamster cells in culture has been studied. The plating efficiency of the culture and the ability to produce a monolayer were used as criteria. The materials under study can be divided into three groups: indifferent materials, those partially inhibiting the cell growth, and destructive ones.