The functional state and electrochemical properties of human blood neutrophil leukocytes after their in vitro interaction with Y. pestis cells, strain EV, was analyzed. A considerable decrease in the electrophoretic mobility of neutrophil leukocytes and a considerable increase in their phagocytic indices was shown. At the same time the maximum phagocytic activity in the total pool of isolated neutrophil leukocytes was registered in fractions having higher electrophoretic mobility. The dependence of electrophoretic mobility on the state of neutrophil membranes, as well as the degree of their activation, is discussed.

sIСАМ-1 was measured in the sera of 156 patients with diffuse toxic goiter (DTG). The majority (105) of these patients presented with clinical signs of autoimmune ophthalmopathy (AO), and the above parameter was measured in order to assess the probability of using it as a criterion of preclinical diagnosis of AO and assessment of the efficacy of its therapy. Five groups of patients were distinguished in the course of study: 1) DTG without AO (n = 27); 2) zero stage of AO (no clinical manifestations) (n = 24); 3) stage I AO (n — 22); 4) stage II AO (n = 60); and 5) stage III AO (n = 23). All patients were in a state of drug-induced euthyrosis; AO of the first-third stages wasttreated traditionally (nonsteroid antiinflammatory drugs, glucocorticoids, radiotherapy of the orbits). Significant changes in sICAM-1 concentration were recorded in DTG patients as early as during the zero stage of AO without apparent clinical signs and confirmed only by computer- aided tomography of the orbits; this result recommends this parameter as an early marker of AO. Serum sICAM-1 content was notably increased in DTG patients with AO, the increase depending on the severity of AO. Changes of si CAM-1 correlated with the clinical picture of the condition (time course of the orbital and muscle index and size of the orbit) and can be used as an additional criterion for assessing the efficacy of treatment of AO.

Lymphocytic blast-cell transformation (LBCT) is shown to be related both to the genotype of a macroorganism and to the genetically determined expression of individual antigens by the plague microbe. The correlation of LBCT with the level of antiinfectious resistance suggests that this index is of high informative value and that it can be effectively used for testing the cellular immunity and the characteristically biological properties of the plague causative agent and its antigens.

The study has examined how the plague bacillus expresses genes of two high-molecular weight (190 and 240 kD) iron-regulated membrane proteins (HMWP). The latter were purified and assayed for their immunobiological properties in vitro and in vivo. DNA-probing (at E.Carniel's Laboratory, Pasteur Institute, Paris) has indicated that Yersinia pestis strains having genes that code for HMWP synthesis circulate in the natural foci of plague which are situated in the former USSR. The use of HMWP in combination with live plague vaccine EV was found to greatly enhance its immunogenicity.

In this work the capacity of Y. pestis, depending on their plasmid composition, for inhibiting the action of the main oxygen-dependent bactericidal systems of macrophages is shown. The data on the modulating influence of Y. pestis on the activity of superoxide dismutase, myeloperoxidase and catalase, the most important enzymes of the synthesis and transformation of cytocidal oxygen radicals, are presented.

The investigation reveals different influence of the plague microbe's fraction 1 polysaccharide-protein complex and of it's purified protein on the 5'-nucleotidase activity and on the chemiluminescence response of peritoneal macrophages. Both of these metabolic indexes were found to be dependent on the dose of fraction 1 and duration of time till examination.