[The determination of antistreptokinase by an immunoenzyme method].

The sensitivity of enzyme immunoassay (EIA) of antistreptokinase, a new method for its measurements, is 10 times higher than the sensitivity of the prototype method. EIA is more sensitive than the prototype method, the incorrectness of the latter being ruled out; endogenous substrates, patients's blood fibrinogen and plasminogen, are used, whose concentrations vary in streptococcal diseases. Effects of nonspecific blood proteinase which, together with streptokinase, may cause a proteolytic effect, on the results of analysis are also ruled out.

[The determination of C-reactive protein by an immunoenzyme method].

The developed enzyme immunoassay of C-reactive protein is based on the use of a plane modified by a phosphorylcholine derivative lisolecithin. The method is highly sensitive (5-8 ng / ml), well reproducible; the correlation coefficients in measurements of blood serum C-reactive protein are compatible to results obtained by rocket immunoelectrophoresis and capillary precipitation: 0.94-0.

[Purification of phospholipase C isoenzyme 1 from Clostridium perfringens and its properties].

A procedure for the purification of isoenzyme I of phospholipase C from Cl. perfringens was developed. The isoenzyme was purified to homogeneity (data from disc electrophoresis) using affinity chromatography on polycephamide and gel filtration through Ultrogel AcA-54, the enzyme yield being 41%.

[Isolation and purification of phospholipase C from Clostridium perfringens and antibodies against it using polymeric biospecific adsorbents].

A new polymeric biospecific adsorbent intended for isolation of Clostridium perfringens phospholipase C (PLC) and PLC-specific antibodies is discussed. It was obtained by radical copolymerization of acrylamide, methylenbisacrylamide, and the acryl acid chloranhydride-acylated substrate of PLC (chicken yolk lecithovitellin). Maximal adsorption of PLC was observed in the presence of the enzyme activator, and the highest amount of PLC was eluted in case of its minimal adsorption.

On the in vitro neutralization test of Clostridium perfringens type A toxin.

Data are presented on the detection in crude animal and human sera of Cl. perfringens phospholipase C (PLC) inhibitor. When the level of Cl.

Comparative study on the immunogenic properties of Clostridium perfringens type A toxoid.

The paper presents the results of a study on the immunogenic properties of toxoid preparations from Cl. perfringens type A obtained using the routine method of detoxifying alpha = toxin in the culture medium (commercial preparations) and by means of detoxifying a previously purified alpha = toxin (experimental preparations). When tested in immunized guinea pigs, the immunogenicity of experimental preparations was found to be 4.

[Comparative evaluation of the methods of determining perfringens A antitoxin].

The methods for determining the level of type A Perfringens antitoxin in human blood sera were examined and compared. The ratios for correlating the data obtained in the toxin neutralization test (NT) in vivo, in the passive hemagglutination test (PHT), and as a result of the enzyme-labeled immunosorbent assay (ELISA) with regard to the antitoxin level measured in the NT in vitro were equal to 0.88, 0.

[Factors modulating production of antibodies against Clostridium perfringens in mammals].

Immunogenic properties of Clostridium perfringens type A toxoid preparations obtained by different methods are described. As regards immunogenicity for guinea-pigs and man, toxoid obtained by the detoxification of preliminarily purified alpha-toxin (experimental toxoid) compares favourably with preparations obtained by the detoxification of alpha-toxin in a culture fluid. It was shown in experiments on guinea pigs that immunogenicity of experimental toxoid rises with the increase in the degree of purification of alpha-toxin used for detoxification.

[Use of the passive hemagglutination test to diagnose toxoplasmosis].

The authors describe a method of obtaining toxoplasma erythrocytic diagnostic agent by sensitization of formalinized tannin-treated SRBC with purified toxoplasma antigen isolated by fractionation of complete toxoplasma antigen on Sephadex G-100. Comparative experiments with titration of sera of persons with suspected toxoplasmosis were conducted; the passive hemagglutination test with the antigen obtained proved to be highly sensitive in comparison with immunofluorescence and complement fixation tests.

[Separation and purification of isoenzymes of Clostridium perfringens phospholipase C].

The procedure for separation and purification of isoenzymes of phospholipase C from Clostridium perfringens (PLC) was developed. The procedure included primary concentration of culture liquid proteins and isoenzyme separtion on DEAE-cellulose during negative sorption of the major isoenzyme. Further purification of the isoenzymes was achieved by (NH4)2SO4 fractionation by Sephadex gel-filtration and isoelectric focusing.

[Homogeneous Cl. perfringens alpha-anatoxin: its physicochemical and immunogenic properties].

The authors present a method of obtaining relatively homogeneous preparations of alpha-toxoid of Cl. perfringens, type A, including the primary conception of the alpha-toxin proteins, their chromatography on DEAE-cellulose, fractionation with (NH4)2SO4, detoxication, with the subsequent gel-filtration through sephadex and isoelectric focussing. Sedimentation coefficient of the preparation proved to be 3.

[Immunogenicity and thymus-dependence of the polymerized alpha-toxoid of Clostridium perfringens].

Polymeric alpha-toxoid with a molecular weight of 450 000--600 000 was obtained by condensation of alpha-toxoid of Cl. perfringens, type A, with glutaric aldehyde. Experiments on guinea pigs showed that in the adsorbed preparations the immunogenic properties of both monomeric and polymeric alpha-toxoids are practically identical.

[The actions of low-molecular fragments of substrate and their analogs on the activity of isoenzymes of phospholipase C from Clostridium perfringens].

The interaction of the lecithin molecule fragments and their analogues with phospholipase C Cl. perfringens was studied by gel-diffusion in agarose-lecithin gels. It was found intense inhibition of phospholipase C activity in the presence of cathionic compounds; this phenomenon shows the existence of anionic centre in the active site of enzyme.

[Immunogenicity of isocomponents of the alpha-toxoid of Cl. oedematiens for mice of opposite reacting genotypes].

There was revealed molecular heterogeneity of the highly purified Cl. oedematiens alpha-toxoid. By the method of isoelectrical focussing alpha-toxoid was divided into isocomponents with the isoelectrical points of 5.

[Characteristics of the immunologic response of animals to Clostridium perfringens anatoxin].

Experiments were conducted on guinea pigs, rabbits and mice (mongrel and inbred); immunogenic properties of Cl. perfringens toxoids of different purity were studied. Toxin neutralization and passive hemagglutination tests were used to determine the antitoxic immunity level.

[Properties of C1. perfringens toxoids obtained from purified toxins].

The authors present the results of comparative study of the properties of experimental perfringens toxoids obtained from purified alpha-toxoids of different degrees of purity. Experimental toxoids proved to possess a greater immunogenicity than preparations obtained by detoxication of alpha-toxin under conditions of cultural fluid, the greater--the more the purity of alpha-toxin used for procuring the experimental toxoid. C1.

[Immune response of mice of different inbred lines to Clostridium oedematiens anatoxin].

Mice belonging to a number of inbred strains were immunized intradermally with Cl. oedematiens alpha-toxoid. The immunization was repeated 30 days later.

[Use of the passive hemagglutination test for the purpose of determining antibody levels following animal immunization with Cl. perfringens toxoid].

Data are presented on the study of possibilities of the application of the passive hemagglutination test for titration of the blood sera of mice, guinea pigs and rabbits immunized with Cl. perfringens toxoid. A diagnostic agent obtained by the sensitization of formalin- and tannin-treated sheep erythrocytes with the serologically pure toxoid, and homologous sera (as standard) were used in this test.