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Biomedical subjects

K Tsankova

Publications and source records attributed to K Tsankova.

15 recordsLinked to original sources
PubMed1986

[Demonstration of ligands for antibodies against the M protein on the virion surface of the Newcastle disease virus (NDV)].

Demonstrated was the presence of ligands for antibodies to the M-protein on the surface of NDV virions, using the hemagglutination-inhibition reaction, the immunodiffusion test in agar gel, the indirect variant of the enzyme-linked immunosorbent assay, and the immunosorbent micromethod with nitrocellulose membranes. Data spoke of transmembrane interactions between the M-protein and the glycoproteins of the envelope, which was of basic importance with regard to the biologic role played by this essential structural virus protein. The presence of ligands made it reasonable to believe that the M-protein played a part in the building up of antiviral immunity.

Animals↗
PubMed1986

[Membrane protein formation in cells infected with the NDV virus and treated with theophylline].

The effect of theophylline on the synthesis of NDV membrane protein which plays an essential role in the production of virions was followed up. It was found that the replication of the virus in chick embryo fibroblasts was inhibited when the cells were treated with 1 mM theophylline. Inhibition was found to concern the final phase of virus replication--the formation of mature infection particles. The amount of membrane protein responsible for virus budding was analogous to that in the cells untreated with theophylline. It is believed that theophylline treatment of cells affects somehow the synthesis of viral proteins and changes their conformation.

Animals↗
PubMed1986

[Isolation of the glycoproteins of the Newcastle disease virus (NDV)].

Two NDV glycoproteins--hemagglutinin-neuraminidase and F-protein--were separated from the remaining structural virus proteins through treatment of the virions with a 2 per cent triton-x-100 and chromatography on a Koh A-sepharose 4B column. A subsidiary ion-exchange chromatography on DEAE--Sephadex technique was employed to separate the two products and obtain them in a pure state. Biologically active NDV glycoproteins were obtained through solubilization of the virions with 10 per cent triton-x-100 at high ion strength, and the two glycoproteins were separated on a DEAE-bio gel column with the use of 0.01 M phosphate buffer of pH 7.2, containing 0.5 M NaCl.

Chromatography, Affinity↗
PubMed1985

[Effect of prostaglandin F2 alpha on the immune response in rabbits].

Investigations were carried out to make clear the effect of prostaglandin F2alfa on forming the primary immune response, using a model of the La Sota antigen. It was found that up to the 48h hour following the use of prostaglandins the immune response decreased, while at the 72nd hour no such drop was observed. It is suggested to pay due attention also to the application of prostaglandin preparations in taking immunoprophylactic measures in cattle breeding and industrial pig farming.

Animals↗
PubMed1981

[Antigenic differences in the glycoproteins of the Newcastle disease virus].

The two glucoproteins of the Newcastle disease virus - hemagglutinin-neuraminidase (HN) and F-protein - were isolated in a pure state from two strains of the virus: the La Sota apathogenic strain and the Roussev strain pathogenic for birds. It was found that the large HN glucoprotein of each of the strains was not identical antigenically with the F-protein. These seemed to be partial antigenic relatedness between the HN of the two strains. On the other hand, the F-proteins of the strains were identical.

Antigens, Viral↗
PubMed1978

[Effect of physical and chemical factors on the antigenic activity of the cell walls of Brucella abortus 99].

Studied was the effect of some physical and chemical factors--heating, acidity, treatment with ultraviolet rays, and enzyme treatment--on the activity of the Brucella abortus 99 cell wall antigen. The activity of the antigen was determined through the microreaction of complement-fixing after Kolmer. It was found that the antigen was most sensitive to acid treatment and treatment with ultraviolet rays, and was more slightly sensitive to the effect of alkaline agents and pronase. Besides, the antigen proved heat-resistant and did not lose its activity after treatment with trypsin and alph- and beta-amylase. The chemical nature of the epitopes (the determinant groups), substantiating the activity of the antigen is briefly discussed.

Amylases↗
PubMed1978

[Soluble regulators produced by the lymphocytes].

Data are given on lymphokins, the biologically active substances lymphocytes when the latter are stimulated with specific antigens or unspecific mitogens. Discussed are their essence, antigen specificity, cell origin, and the methods of purification, standardization, and evaluation of biologic importance. It is believed that the lymphokins appear to be the products of primary activation of T lymphocytes. They possess pharmacologic activity, but have no antigenic specificity. Their function consists in mediating hypersensitive and inflammatory reactions through the activation of phagocytes. The effectiveness of cellular immunity depends on the activity of these factors.

Animals↗
PubMed1978

[Antitumor activity of the bacterial walls of Br. abortus 99].

A brief chronologic survey is made of investigations that reveal that the bacterial cell walls and their chemical components exhibit antitumoral activity. Discussed is the problem which are the constituents of the bacterial wal and what is the mechanism through which such effects are produced. The conclusion is drawn that some peptides participating in the structure of the bacterial wall after their release in body stimulate the macrophages and thus confer antitumoral activity to them.

Antineoplastic Agents↗
PubMed1977

[Chemical and serological studies of Brucella abortus 99 bacterial wall fractions].

Mahadevan and Tatum's method was used to isolate four fractions from the bacterial walls of Brucella abortus 99. Determined were the amino acid composition and the purity (by means of the complement fixation test) of these fractions. Infrared spectroscopy was carried out as well. It was found that: 1. The particular fractions differ by their amino acid composition. 2. The fractions are practically pure. 3. The functional groups established confirm previous data of the author on the chemical composition of the wall, and give an idea about the distribution of these groups among the individual fractions. The fractions obtained prove to be the building ingredients of the Brucella abortus 99 bacterial wall.

Amino Acids↗
PubMed1976

[Chemical and immunologic study of the bacterial wall of Brucella abortus 99].

The investigations were carried out through the CFT serologic activity of some of the Brucella abortus 99 cell components. It was found that only 0.6 per cent of the weight of the bacterial walls could be extracted by means of physiologic saline. The extracts proved to be serologically active and specific for these Brucella organisms only. The wall of Brucella abortus 99 and its peptidoglucan were shown to be rich in lysine, leucine, glitamic acid, and valine, and poor in methionine, histidine, treonine, and, generally, in sulfur-containing amino acids. The presence of higher content of lysine and glutamic acid explained the higher resistance of the bacterial walls of Brucella abortus 99 as compared to that of M. Lysodiecticus. The wall of Br. abortus 99 contains high amounts of phosphatidil acids - 16.4 per cent of the total amount of lipids. The biologic importance of the results obtained is briefly discussed.

Amino Acids↗
PubMed1975

[Adjuvant activity of the peptidoglycan isolated from the bacterial wall of Brucella abortus 99].

Cell walls were obtained from Brucella abortus 99. A peptidoglucan was isolated from them. Test animals were immunized (albino mice) with pure human gammaglobulin, and in a series of experiments the peptidoglucan was added to the antigen, while in another one it was injected 24 hours later. The titer of the separated serum was determined in terms of the amount of the complement-fixing antibodies present, using the microreaction of complement fixation. It was established that with the addition of the peptidoglucan to the antigen the titer of the newly produced antibodies rose several times. If injected later (24 hours) it did not affect the production of antibodies. Discussed is the mechanism substantiating the rise of the antibody level.

Adjuvants, Immunologic↗