Biomedical subjects
Publications and source records attributed to A S Novokhatskiĭ.
In 4 Francisella tularensis strains varying in virulence a receptor to Fc site of human IgG has been detected. This receptor consists of two active components with molecular weights of 67,000 and 40,000, competing for binding on Fc site of human IgG with Staphylococcus aureus protein A.
On the grounds of clinico-physiologic investigations the author revises the existing dual theory of photoreception. The paper describes complex clinical investigations of visual functions in patients with alimentary and essential hemeralopias and shows that rods and cones do not function in conditions of scotopic illumination without the presence of rhodopsin. On the grounds of investigations of the phenomenon of inversion and depression in the short-wave part of the visible spectrum in normal persons after dark adaptation in conditions of scotopic illumination, the author comes to a conclusion that there is a so-called "rhodopsin filter" just the presence of which in the process of dark adaptation creates conditions for appearance of this phenomenon. The author believes that there exist two kinds of photoreception: a direct disc two-component and a mediated rhodopsin one-component, as well as the third, transitory, that corresponds to those conditions of illumination in which the Purkinje's phenomenon appears.
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The paper describes data on conditions for appearance of a physiologic central retinal scotoma of dark adaptation. Examinations of 80 eyes with normal visual functions have shown that central scotoma of dark adaptation is revealed in conditions of scotopic illumination 20-25 minutes after dark adaptation. The optimal duration of dark adaptation is 40-45 minutes. More frequently scotoma is displaced upwards from the point of fixation, its sizes varying from 4 degrees to 10 degrees by the horizontal meridian and from 3 degrees to 8 degrees by the vertical meridian. The presence of this scotoma should be considered when examining the state of the visual analyser in conditions of scotopic illumination. This can play a certain role in differential diagnostics of clinical ophthalmopathology.
Preparation of highly active rabbit antisera (AS) to human recombinant alpha 2-interferon and their use for studying biological properties of natural and plasmid alpha-interferons are described. By exhaustion of AS by alpha 3-interferon there were prepared practically monospecific AS not reacting with antigenic determinants of alpha 3-interferon. It was found that alpha 3-interferon represented a significant portion of human lymphoblastoid interferons and was included in PH-labile alpha-interferon from serum of patients with Kaposi carcinoma. AS to alpha 2-interferon completely neutralized antiviral and antiproliferative activity of the homologous subtype alpha-interferon and stimulation of cytotoxicity of human natural killer cells induced by it. It neutralized also the same effects of the heterologous subtypes (alpha 3 and alpha F/D) and leukocytic interferon, but the neutralization level was lower. The results of the study confirmed the polyfunctional nature of the interferon molecule.
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A highly technological Yel-2 hybrid cell clone was isolated. The clone produces monoclonal antibodies to protein E of the yellow fever virus (Dakar strain). The Yel-2 hybridoma was cloned by the method of limiting dilutions. By the data of indirect immunofluorescence the titre of the specific antibodies reached 1:128 in the culture fluid and 1:10240 in the ascitic fluid. The Yel-2 antibodies had no cross reactions with forest-spring encephalitis, Dengue 2 and Dengue 4 viruses. In the hemagglutination inhibition test the activity of the Yel-2 ascitic preparations was observed at a dilution of 1:50000 while the complement fixation test did not reveal it. Administration of the Yel-2 cells into the abdominal cavity of mice BALB/c induced development of ascitic tumors in 97 per cent of pristane-sensitized mice and in 90 per cent of nonsensitized mice. The hybridoma was successfully transplanted from mouse to mouse (more than 20 passages during the observation period) and maintained high constant levels of specific antibody secretion. The high ascite forming capacity of the Yel-2 hybridoma provided decreasing of the cell dose administered to the mice from 10(7) to 10(4) cells per mouse.
The optic nerve of the dog has been histologically studied. In the intact nerve 160,000 axons have been revealed. In 3 weeks after the nerve section in the orbit and near the nerve disk 72% retinoencephal fibers, 28% encephaloretinal and 0.23% of centrofugal axons are found.
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The specific activity of diagnostic preparations based on monoclonal IgM MAK-14-7 interacting with the antigens of the Venezuela equine encephalomyelitis virus, monoclonal IgG KAMA-51 interacting with the antigens of the forest spring encephalitis virus and monoclonal IgA OKA and IgM OKA binding to the antigens of the vaccine virus was studied by the enzymatic immunological and immunofluorescent tests. Both the ascitic preparations of the antibodies and the fluorescein isothiocyanate-conjugated reagents such as MAK-FITC, KAMA-FITC and OKA-FITC were characterized by high specificity and activity. The specific sensitivity and activity of the monoclonal immunoglobulins was completely maintained in the mixed and combined preparations.
A panel of 6 hybridomas "XEJIMA" producing monoclonal antibodies specific to HeLa cells is prepared. Monoclonal antibodies do not bind to antigens of human diploid fibroblasts, human continuous B- and T-lymphocytes and animal cell lines. The specificity of monoclonal antibodies to cellular antigens of 5 HeLa-like cell lines and 6 human tumour cells lines, not contaminated with HeLa cells, is determined. Antibody containing ascitic fluid and culture media of hybridomas XEJIMA-3, -12, -13, and -22 significantly decrease the attachment of HeLa cells to the surface of culture flasks. Monoclonal antibodies XEJIMA-11, -12 and -13 block the multiplication of HeLa cells. The effect depends on serum concentration in the nutrient medium.
The conditions of immunoenzyme assay have been studied on the solid state phase of infected cells using the model of monoclonal antibodies MAK-14-7 to the virus of Venezuelan equine encephalomyelitis (VVEE) and monoclonal antibodies OKA-1 to vaccine virus in the systems of VNK-21 cells or 4647 cells infected by VVEE, or HeLa cells infected by vaccine virus. The titer of monoclonal antibodies detected grows with the dose of infected cells fixed in the holes of micropanel used for reaction and with the multiplicity of infection. The most intensive and contrasting dyeing of conjugate has been registered when the cells have been fixed with 0.25% glutaraldehyde 24 h after infection. The titers of ascytic preparations of monoclonal antibodies MAK-14-7 and OKA-1 under the optimal conditions of immunoenzyme assay reaction on the solid phase of infected cells present 1 : 10 000 and 1 : 100 000.
The conditions of the formation of ascitic cells in BALB/c mice injected with hybridoma cells were studied. All the hybridomas under study, producing monoclonal antibodies to viral antigens, induced the formation of ascitic tumors when introduced into the abdominal cavity of BALB/c mice pretreated with sensitizing agents. In the mice pretreated with pristane hybridoma cells took at a rate of 43-80% and in the mice pretreated with Freund's complete adjuvant, 31-70%. Angara oil and perfume oil, as well as Bayol F, were less effective. The time of the formation of ascites was inversely proportional to the dose of the injected cells, while the volume of ascitic fluid depended rather on the type of hybridoma and not on the dose of the injected cells. The study showed that the use of physiological saline or culture medium without serum for washing the abdominal cavity of mice after withdrawing ascites permitted the additional collection of 2.6-13.7 million hybrid cells, as well as a considerable amount of immunoglobulins.
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