[Current aspects of the clinical picture of tick-borne encephalitis].

Based on the long-term follow-up of 655 patients with different forms of tick-borne encephalitis (TBE), the authors describe its present clinical characteristics in the Baikal natural focus. They have established the preponderance of the meningeal form of the infection and the relatively severe course with residual phenomena and a fatal outcome in patients with the poliomyelitic form of TBE.

[The experience of diagnosis, treatment and prophylaxis of gastric and duodenal ulcer in outpatient conditions].

Gastric and duodenal ulcer (peptic ulcer) takes the leading place among the pathology of digestive organs. According to the data of specialists from Consulting-and-Diagnostic Center N 52 among the servicemen with chronic diseases the digestive pathology constitutes 32%. Among these diseases the peptic ulcer occurs in 81% cases. Screening esophagogastroduodenoscopy conducted in 1100 servicemen without any complaints aged 22-50 has revealed duodenal ulcer in 5.4%, gastric ulcer--in 0.7% and gastroduodenitis--in 11.4%. With introduction of modern methods of diagnosis, treatment, rehabilitation and prophylaxis of peptic ulcer 98% patients with disease uncomplicated course began and completed treatment in outpatient conditions.

[Clinical and laboratory characterization of Ixodes tick-borne borreliosis in the Baikal area].

Materials on Ixodes tick-borne borreliosis (ITB) for the period of 2000 - 2003 (i.e. 1,222 blood serum samples from patients with acute ITB and 629 patients with chronic ITB) were analyzed. The proportion of seropositive samples among those obtained from patients with acute and chronic ITB was determined with the use of the indirect immunofluorescence test. In addition, data on different clinical forms of the disease were presented. A high percentage of neurological manifestations in the early period of ITB (31%) and in the late period of the disease (72.8%) was noted. The conclusion was made concerning the necessity of using several diagnostic methods for more exact determination of the structure of the disease.

[Gram-negative virulent bacterial lipopolysaccharide: role in infection and immunity]. / Lipopolisakharidy gramotritsatelnykh virulentnykh bakterii i ikh rolv infektsii i immunitete.

The paper discusses the data available in the literature on the studies on lipopolysaccharides (LPS) of bacteria which show their different virulence. A comparative study of the chemical composition and structure of LPS of the bacteria fails to detect any great difference, but they differ in their biological, especially immunobiological properties. It is suggested that the differences are associated with LPS conformation, chiefly its lipid moiety and ion-coordinating processes and free radical reactions are involved in the conformation. Examining just these phenomena may made advances in further studies of virulent bacterial LPS and possibilities of its use while designing new-generation vaccines.

[Immunosuppressive effects of pathogenic gram-negative bacteria]. / Immunosupressivnoe deistvie patogennykh gramotritsatel'nykh bakterii.

The review deals with the Immunosuppressive effects of virulent gram-negative bacteria (Salmonella, Shigela, Pseudomonas aeruginosa), with the importance of these effects for the bacteria to survive in the infected body. The above bacteria affect the immunity system in a different way, yet have common features. They are characterized by the occurrence of endotoxin shock, by the suppression of the phagocytic system and cell-mediated immunity. A significant role in suppressing a cellular immune response is played by the lipopolysaccharide of virulent bacteria that greatly differs from that of nonvirulent strains. The immunosuppressive activity of the bacteria and their lipopolysaccharide is closely related to their virulent properties.

[Suppressive action of the influenza virus on the cellular immune reaction]. / Suppressivnoe deistvie virusa grippa na kletochnuiu immunnuiu reaktsiiu.

Experiments in mice using syngeneic transfer of spleen cells and intraperitoneal inoculation of cyclophosphamide, levamisole, hydrocortisone, and anti-0 serum demonstrated that influenza virus may inhibit T-suppressors from the first days of infection. Then the T-helper system of lymphocytes is inhibited and the capacity of the animals to show delayed type hypersensitivity is reduced. In this period, higher activity of T-helpers is observed. It is assumed that inhibition of the T-helper system is associated with the affection by influenza virus of the cells which activate T-helpers.

[Immunosuppressive properties of the influenza virus]. / Immunosuppressivnye svoistva virusa grippa.

In experimental influenza infection in mice, inhibition of generation of antibody and antibody-producing cells was observed against reduced activity of T-suppressors and activation of T-helpers. These data indicate that the immunosuppressive effect of influenza virus is associated with inhibition of some other elements in the lymphocyte T-system rather than T-helpers.

[Relation of the immunosuppressivity of virulent Shigella to the structure of O antigen]. / Sviaz' immunosupressivnosti virulentnykh shigell so strukturoi O-antigena.

The capacity of filtrates of virulent Shigella cultures (VSC) and their different fractions to render avirulent strains, injected intraperitoneally into mice simultaneously with these filtrates, capable of suppressing immune response (delayed hypersensitivity) has been studied. Among the fractions of VSC filtrates, the lipoid fraction soluble in the mixture of ethanol and ether has proved to be active. Active factors can be extracted from VSC filtrates by means of immunosorbents obtained from antibodies of pertinent specificity. VSC filtrates are completely inactivated by treatment with phenol and trichloroacetic acid. These data suggest that the immunosuppressive factors of shigellae, responsible for their capacity to suppress immunological memory, are incorporated into the O-antigen of these bacteria.

[Shigella toxicity in immunological tolerance]. / Toksichnost' shigell pri immunologicheskoi tolerantnosti.

The toxic effect of killed and live Shigella sonnei cultures on normal mice and on mice, tolerant to Shigella O-antigen and to human erythrocytes of different blood groups (in the ABO system) was under study. The toxicity of shigellae, introduced intraperitoneally, has been found to depend on their viability, on their capacity for penetration into the blood, and on the split character of immunological tolerance to Shigella antigens.

[Detection of immunosuppression factors in Shigella sonnei]. / Vyiavlenie faktorov immunosupressivnosti u Shigella sonnei.

A factor, making noninvasive shigellae and other bacteria capable of suppressing immunological memory and secondary immune response manifested as delayed hypersensitivity, has been detected in the germ-free filtrates of the broth cultures of invasive S. sonnei.

[Lipopolysaccharides of Shigella sonnei]. / Lipopolisakharidy Shigella sonnei.

Immunobiological properties of native lipopolysaccharides (LPS) from virulent and avirulent strains of Shigella sonnei bacteria (LPS-V and LPS-A, respectively) were studied. In avirulent bacteria, LPS-V induced immunosuppressive activity specific of the virulent strain. LPS of the avirulent strain, whereas LPS-A lacked this property. Native LPS-V with immunosuppressive activity were isolated from the virulent strain by and immune affinity method. Treatment of LPS-V with phenol or TCA abolished its activity and converted it into the LPS-A form. The data showed that LPS-A can be converted back to the LPS-V form by redox treatment. This approach seems to be promising for activating LPS extracted from cells with TCA or a water-phenol mixture.

[Nonspecific Shigella suppression of delayed hypersensitivity]. / Nespetsificheskaia shigelleznaia supressiia giperchuvstvitel'nosti zamedlennogo tipa.

Experimental study in mice has revealed that live virulent shigellae, in contrast to killed ones, suppress the secondary immune response to guinea pig splenocytes, manifested as delayed type hypersensitivity. This suppression is caused by disturbances in the process of the realization of the existing immunological memory: avirulent shigellae have been proved to cause no such effect.

[Suppression of the immune response by Shigella in experimental influenza infection in mice]. / Supressiia immunnogo otveta shigellami pri éksperimental'noi grippoznoi infektsii u myshei.

Experiments in mice have demonstrated that in the presence of influenza infection the suppressing effect of virulent shigellae on the secondary humoral and cell-mediated immune response is enhanced. Under such conditions avirulent shigellae can also show suppressing effect which is usually absent in these organisms.

[Significance of bacteremia in the development of immunological memory suppression in Shigella sonnei infection in mice]. / Znachenie bakteriemii v razvitii supressii immunologicheskoi pamiati pri infektsii Shigella sonnei u myshei.

Experiments on mice infected intraperitoneally with S. sonnei have revealed that the level of bacteriemia is directly related to the duration of the blocking of immunological memory constituting the basis of secondary humoral and cell-mediated immune response. The transfer of syngeneic splenocytes from immunized mice has demonstrated that virulent S. sonnei directly affect the immunological memory cells.

[The immunosuppressive activity of Shigella sonnei differing by the presence of plasmid pSS120]. / Immunosupressivnaia aktivnost' Shigella sonnei, razlichaiushchikhsia po nalichiiu plazmidy pSS120.

S. sonnei virulent strain containing invasiveness plasmid pSS120 was found to suppress delayed hypersensitivity (DH) to nonbacterial antigens. In the filtrate of the culture of this strain extracellular lipopolysaccharide (LPS), capable of inducing immunosuppressing activity in nonvirulent bacteria, was detected. S. sonnei strain having plasmid pSS120 whose invasiveness genes were blocked by the penetration of transposon Tn5, as well as strains containing no invasiveness plasmid, proved to be nonvirulent and could not inhibit immunosuppressing action. Extracellular LPS of nonvirulent strains had no inductive immunosuppressing activity. But it could be activated by chemical treatment. The results of this study indicate that the immunosuppressing action of S. sonnei LPS were linked with some genes of invasiveness plasmid pSS120.

[Dependence of immunosuppressive action of lipopolysaccharide on degree of Salmonella pathogenicity]. / Zavisimost' immunosupessivnogo deistviia lipopolisakharida ot stepeni patogennosti sal'monell.

Immunosuppressive activity of Salmonella typhimurium extracellular lipopolysaccharide (LPS) was studied. In this study isogenic S. typhimurium strains with different degree of virulence were used. The attenuation of these strains was linked with mutations on their chromosome (altered synthesis of RNA polymerase or gyrase DNA) or their own virulence plasmid (the insertion of transposon Tn-5). To obtain LPS fraction with different molecular weights, the filtrate of bacterial culture was subjected to gel filtration through a column packed with Sephadex G-200. The immunosuppressive action of LPS fractions was determined on the model of delayed-type hypersensitivity to nonbacterial antigen in experiments on BALB/c mice. The study revealed that transposon-mediated mutation on plasmid, accompanied by the attenuation of salmonellae, led to the loss of immunosuppressive activity of the high-molecular heat-sensitive component of LPS; only the second heat-resistant component with medium molecular weight retained its activity. The presence of two chromosomal attenuating mutations (rifr nalr) was accompanied by the loss of immunosuppressive activity in both components of LPS.

[The immunosuppressive action of different fractions of Salmonella typhimurium lipopolysaccharide]. / Immunosupressiruiushchee deistvie razlichnykh fraktsii lipopolisakharida Salmonella typhimurium.

The suppressing activity of lipopolysaccharide (LPS) of the filtrates of genetically related S. typhimurium 415 and 415/307 cultures with respect to delayed hypersensitivity to nonbacterial antigen in mice was studied. In LPS of the virulent strain two immunosuppressing fractions differing in their molecular weight were detected by the method of gel filtration. One of them was detected in LPS of the genetically related nonplasmid clone of S. typhimurium 415/307. The possibility of the chemical inactivation and reactivation of the immunosuppressing properties of LPS was shown.

[The immunosuppressive activity of Streptococcus aureus peptidoglycan]. / Immunosupressivnaia aktivnost' peptidoglikana Staphylococcus aureus.

The immunosuppressive activity of peptidoglycan, obtained from S. aureus was studied in mouse experiments on the model of delayed hypersensitivity (DH) to guinea pig antigens. The study revealed that PG suppressed DH, this action being linked with its insoluble fraction. The soluble part of PG did not suppress DH. Experiments with the use of immunosorbent demonstrated the existence of serological similarity between the active factor of the soluble part of PG and its insoluble part.

[Microcirculatory function in viral hepatitis A and B]. / Sostoianie mikrotsirkuliatsii pri virusnykh gepatitakh A i B.

Microcirculation was studied over time in 51 patients with acute viral hepatitides types A and B using bulbar microphotographic vasography. The results were compared with some immunological indices (the blood level of circulating immune complexes, the platelet aggregation test). The expression of microcirculatory changes correlated both with a type of virus hepatitis and the severity of disease. The relationship of disorders in the system of microcirculation with immune factors, in particular with immunopathological reactions developing during HBV infections, was discussed.