[Use of neuraminidase for improving the properties of the erythrocytic ganglioside diagnosticum]. / Ispol'zovanie neiraminidazy dlia uluchsheniia svoistv eritrotsitarnogo gangliozidnogo diagnostikuma.

In this work the possibility of using neuraminidase for increasing the content of ganglioside GM1 in the mixture of gangliosides used for the sensitization of erythrocytes has been studied. The study has revealed that the treatment of gangliosides with neuraminidase is sufficient for obtaining active hemosensitin; there is no need for the purification of the preparation by gel filtration.

[Use of the toxin-tissue receptor reaction for detecting toxic substances of the causative agents of acute intestinal diseases]. / Ispol'zovanie reaktsii toksin-tkanevyi retseptor dlia obnaruzheniia toksicheskikh substantsii vozbuditelei ostrykh kishechnykh zabolevanii.

The possibility of using erythrocytic ganglioside diagnostic reagents (EGDR) for the detection of V. cholerae, E. coli and S. typhimurium enterotoxins in the passive hemagglutination (PHA) test has been shown. Museum strains and cultures isolated from patients with acute intestinal diseases were tested for the presence of enterotoxins. Cell-free extracts were studied by biological methods and by serological titration in the PHA test with the use of EGDR. The diagnostic reagent was found to interact only with those enterotoxins whose specific receptors were gangliosides GM1.

[Production of an erythrocytic ganglioside diagnostic reagent for detecting cholera enterotoxin and toxoid in indirect hemagglutination tests]. / Poluchenie éritrotsitarnogo gangliozidnogo diagnostikuma dlia vyiavleniia kholernogo énterotoksina i toksoida v reaktsii nepriamoi gemagglutinatsii.

The studies described in this work have indicated that cholera enterotoxin and its components (cholerogenoid and subunit B) can be detected in amounts of 0.25, 0.28 and 0.6 microgram of protein per 1 ml, respectively, by means of erythrocytes sensitized with gangliozide-containing complex. The conditions for erythrocyte sensitization have been established. The methods of cholerogen titration in the passive hemagglutination test by means of the erythrocytic gangliozide diagnostic reagent and in Craig's skin test have been shown to correlate. Similarly, the passive hemagglutination test is supposed to be suitable for detecting other bacterial toxins interacting with gangliozides.

[Method of extracting cholera toxin from solid media containing cultured vibrios]. / Sposob izvlecheniiia kholernogo toksina iz plotnykh sred pri vyrashchivanii na nikh vibrionov.

The possibility of obtaining biologically active cholerogen by extracting it from solid culture media used for the cultivation of vibrios is shown. V. cholerae, strain 569B, cultivated on solid media produced about 3 times more toxin per 1 ml of the culture medium than during the process of its cultivation with the use of liquid culture media. The inculation temperature proved to have no essential influence on the toxin production by vibrios.

[Possibility of purifying cholera toxin (choleragen) and its antibodies by an immunosorption method]. / Izuchenie vozmozhnosti ochistki kholernogo toksina (kholerogena) i antitel k nemu metodom immunosorbtsii.

A study was made to establish the possibility of using an immune adsorbent based on polyacrylamide gel with the concentration of T = 10% and C = 25% for the purification of cholerogen and antibodies to it. For the isolation of cholera toxin the gamma globulin fraction of antitoxic serum was incorporated into the adsorbent; for obtaining antibodies an adsorbent with partially purified cholerogen was used. Desorption was made with 3 M sodium rhodanide solution. The yield of cholerogen was 41%, and the yield of antibodies was 4.5%. The non-specific sorption of the immune adsorbents was insignificant.