[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.

[Immunoglobulins and their specific activity in cholera]. / Immunoglobuliny i ikh spetsificheskaia aktivnost' pri zabolevanii kholeroi

The authors studied the quantitative content of nonspecific immunoglobulins and antibodies of the IgG-, IgA-, and IgM-classes to the O-antigen of the cholera vibrio. There proved to be no marked dynamics of the quantitative immunoglobulins indices of various classes established at periods from the 3rd and the 18th day from the beginning of the disease in persons who sustained cholera. In persons who sustained cholera in the nonendemic focus of the disease serum antibodies were represented chiefly by the IgM-antibodies. The formation of IgA-antibodies in the persons examined differed from the regularities detected for the IgG- and IgM-classes and were characterized by rapidity and short duration. No correlation was found between the immunoglobulin levels of various classes and the serum antibody levels in case of cholera affection.

[Avidity of specific antibodies in the sera of cholera patients and vibrio carriers]. / Izuchenie avidnosti spetsificheskikh antitel v syvorotkakh krovi bol'nykh kholeroi i vibrionositelei

Avidity of specific antibodies was studied in the sera of patients suffering from cholera and vibrio-carriers by the rate of antibody binding (in the bacterial agglutination reaction) and by the completeness of their binding with O-antigen (in the passive hemagglutination test). There were revealed statistically significant higher indices of antibody avidity contained in the blood sera of the vibrio carriers, in comparison with the antibodies in the blood sera of patients with clinically manifest forms of cholera. There proved to be an increase in the antibody avidity in the dynamics of the infectious process. It is supposed that the degree of avidity of anticholera antibodies in examination of whole sera depended on the ratio of the specific macro- and microglobulins in them.

[Use of the thrombocyte aggregation test for detecting immune complexes circulating in the serum of cholera patients]. / Ispol'zovanie testa agregatsii trombotsitov dlia obnaruzheniia immunnykh kompleksov, tsirkuliruiushchikh v syvorotke krovi bol'nykh kholeroi

It was shown that the blood sera of patients suffering from cholera and of persons who had sustained the disease contained specific antibodies in titres below the diagnostic level (according to the indirect hemagglutination test) caused platelet aggregation, most pronounced during the first week of the infectious process. In the presence of a specific cholera antigen the phenomenon of platelet aggregation was considerably enhanced; the indices reached the maximum when the experiment was conducted with the blood sera of those who had sustained the disease.

[Utilization of serological methods in the retrospective diagnosis of cholera and in detecting vibrion carriers]. / K voprosu ob ispol'zovanii serologicheskikh metodov v retrospektivnoi diagnostike kholery i pri vyiavlenii vibriononositelei

Sensitivity and specificity of the three serological methods were studied comparatively: the vibriocidal test, the reaction of bacterial agglutination and of indirect hemagglutination, with the use of erythrocytes sensitized with the vibrio lyzate, cholera species O-antigen and cholerogen. Investigations were conducted with the blood sera of cholera patients, vibrio carriers and contacts. Vibriocidal test proved to be the most sensitive; its data correlated with the results of bacterial agglutination and indirect hemagglutination with erythrocytes, sensitized with the lysate of the vibrios and the cholera O-antigen. None of the used serological methods provided a 100% coincidence with the results of bacteriological analysis. The frequency of detection of anticholera antibodies decreased in the following order: cholera patients, vibrio carriers, contacts.

[Differences in certain immunological indices among persons who have had cholera and among Vibrio carriers]. / Razlichiia v nekotorykh immunologicheskikh pokazateliakh u lits, perenesshikh kholeru, i vibriononositelei

Blood sera of persons, who sustained cholera of different degree of severity, and of vibrio-carriers, and also chromatographic fractions obtained in separation of the mentioned sera on DEAE-cellulose were investigated in the reaction of agglutination and the indirect hemagglutination test. Immunological response in the vibrio carriers was realized by the microglobulin, and in the convalescents--by the macroglobulin type. There was also revealed an association between the severity of the course of cholera and the prevalence in the blood serum of one or another type of specific antibodies: in severe forms of the disease the antibodies of the IgM-class were detected with the greatest frequency, and microglobulin antibodies--in vibrio carriers. The detected differences in the immunological status of those who sustained cholera and of vibrio-carriers could be used as an additional differential sign in the diagnosis of the mentioned conditions.