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Biomedical subjects

Iu V Ezepchuk

Publications and source records attributed to Iu V Ezepchuk.

At least 19 recordsLinked to original sources
PubMed1992

[Changes in the content of reduced glutathione in the liver of mice under the action of staphylococcal enterotoxin type A and lipopolysaccharide].

We investigated the level of reduced glutathione in mouse liver after injection of staphylococcal enterotoxin type A (SEA) and Serratia marcescens endotoxin (LPS). It was shown that SEA caused significant glutathione depletion. Glutathione level fell more under the combined treatment by both toxins. The data demonstrate a considerable role of antioxidant potential in the mechanism of enhanced sensitivity of animals to the lethal effect produced by LPS.

Animals↗
PubMed1991

[The use of the aggregate hemagglutination reaction and immunoenzyme analysis in determining staphylococcal enterotoxin type D].

Type D purified staphylococcal enterotoxin and anti-enterotoxic serum to it were prepared. IgG isolated from the anti-enterotoxic serum by the affinity chromatography method was used to improve the specificity and sensitivity of the aggregate hemagglutination test (AHAT) and enzyme immunoassay (EIA). The developed AHAT and EIA variants intended for the indication of type D staphylococcal enterotoxin are characterized by a high resolution ability and strict specificity. The suggested methods are simple and may be used for the rapid diagnosis of staphylococcal toxin infections.

Enterotoxins↗
PubMed1991

[A simple method of purifying staphylococcal alpha-toxin and a study of its properties].

The simple method is proposed for isolation and purification of staphylococcal alpha-toxin that permits one to obtain the homogeneous toxic protein with high activity. The time necessary for maximal toxin production at cultivation has been defined. The thermostability and interferonogenic characteristics of the obtained alpha-toxin were studied.

Bacterial Toxins↗
PubMed1991

[Isolation and certain properties of the dermonecrotic toxin from Pasteurella multocida].

The procedure for isolation and purification of Pasteurella multocida serovariant D toxin has been described. It includes the three steps of protein precipitation from cultural filtrates by 70% ammonium sulfate, chromatography of the concentrated material on Ultragel AcA44 gel-filtration on Sephracryl S-200. The proposed technique permits one the 155-fold purification of the preparation with 32.6% yield estimated by biological activity. The obtained purified preparation is homogeneous in polyacrylamide gel electrophoresis. The immunological methods also confirm the homogeneity of the preparation. The minimal dermonecrotic dose for guinea pigs of the purified 120 kDa toxin is 78 ng and LD50 for mice is 280 ng. Pasteurella multocida toxin is found to be a thermolabile protein sensitive to trypsin, glutaraldehyde and formaldehyde treatments.

Animals↗
PubMed1991

[The antilysozyme activity of meningococci].

The antilysozyme activity of 184 meningococcal strains was studied. Such activity was found in all strains within the range 1-25 micrograms/ml, which was due to the heterogeneity of bacterial population. Strains varying in the total level of their lysozyme activity differed in the population structure by this sign. Preparations inhibiting antilysozyme activity could be differentiated according to the character of their action by the method of the population analysis. In the process of phagocytosis the selection of clones with a high level of antilysozyme activity was found to occur. The antilysozyme factor, heat resistant protein with a molecular weight of 10,000-30,000 D, was sensitive to trypsin.

Bacterial Proteins↗
PubMed1990

[Purification and various properties of Vibrio cholerae NON-01 cytolysin].

A new method for isolation and purification of Vibrio cholerae non-01 cytolysin has been elaborated. It includes the steps of concentration by ammonium sulphate, ion exchange chromatography on DE-52-cellulose, gel filtration via ultragel AsA-44 and chromatography on Mono Q. Cytolysin is shown to be a 60 kD and pI 6.2 protein. It is not inactivated by thiol-restoring agents and induces the production of precipitating antibodies. In contrast to choleragen the protein cytolytically affects erythrocytes and cells of the line L-929. It also possesses the lethal and oedematous effect and demonstrates the enteropathogenic effect on nursing rabbits.

Animals↗
PubMed1990

[The enterotoxigenic capacity of hemolysin-producing strains of Proteus isolated in acute intestinal infections in children].

The capacity of P. mirabilis and P. vulgaris strains isolated in acute enteric infections in children for producing enterohemolysin, a new type of hemolysin, has been shown. The relationship between the capacity of Proteus cultures for producing enterohemolysin and their capacity for inducing toxic secretory reaction on a ligated loop on the small intestine of rabbits in the absence of known thermostable and thermolabile antitoxin in bacteria.

Acute Disease↗
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

[Immunobiological properties of staphylococcal enterotoxins type A, B, C, D and E].

Comparative study of mitogenic and interferonogenic properties of staphylococcal enterotoxins of different serotypes is done. It is revealed that preparations of enterotoxins are polyclonal mitogens and have interferon-inducing activity. It is stated that enterotoxin of D type has the highest mitogenic activity, which is shown by interferon-inducing activity of A type toxin.

Antigens↗
PubMed1989

[The detection of a choleriform thermolabile enterotoxin in clinical strains of Proteus isolated in different infections].

The capacity of Proteus strains, isolated from patients with purulent inflammatory, urological and enteric infections, for the production of choleriform thermolabile enterotoxin was studied by means of the enzyme immunoassay (EIA) with the use of antitoxic serum to Escherichia coli enterotoxin. Out of 125 strains, 27 (21.6%) showed the capacity for producing choleriform thermolabile enterotoxin in EIA experiments. The results thus obtained indicate that EIA techniques can be used, in principle, for detecting the capacity of Proteus for the production of choleriform thermolabile enterotoxin.

Acute Disease↗
PubMed1989

[Lowering of bactericidal activity of mouse peritoneal macrophages under combined use of staphylococcal enterotoxin type A and endotoxin].

The present study investigated the effect of staphylococcal enterotoxin type A (SEA) and endotoxin Serratia marcescens (LPS) on the phagocytosis and killing of Staphylococcus aureus by mouse peritoneal macrophages. Two hours after enterotoxin intraperitoneal injection phagocytic and bactericidal activity were depressed. 24 hours later there was increased functional activity of macrophages by SEA and LPS, apart. But when two toxins were administered together (LPS four hours later enterotoxin) marked inhibition of bacterial killing was observed. When peritoneal macrophages were treated in vitro for 24 hours with the same toxins they were also markedly suppressed in bactericidal activity.

Animals↗
PubMed1989

[Staphylococcal enterotoxin type E: isolation, purification, identification].

Homogeneous protein of staphylococcal enterotoxin type E has been isolated. The technique of isolation, permitting 48% yield of active material, includes concentration by ammonium sulfate precipitation, ion exchange chromatography on DEAE-cellulose and gel-filtration on sephacryl S-200. The molecular mass of the isolated protein is 32 Kd. Antigenic affinity of staphylococcal toxins types A and E has been established by immunochemical analysis.

Chromatography, Ion Exchange↗
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↗