[Electron microscopic study of the cytopathogenic action of meningococci in a continuous human amnion cell culture]. / Elektronno-mikroskopicheskoe izuchenie tsitopatogennogo deistviia meningokokkov na perevivaemuiu kul'turu kletok amniona cheloveka.

The electron-microscopic study of the interaction of meningococci with continuous human amnion cell culture F1 has revealed that this process comprises 3 stages. The study has shown that, following the adhesion of meningococci to the surface of cells F1, these cells are invaded by individual coccal forms of meningococci. In response to infection vacuoles appear in the cytoplasm of the cells. Meningococci are either phagocytosed inside these vacuoles, or their release into the intercellular space and the death of the infected by meningococci are observed. When the cells are infected by cytopathogenic strains, the infectious process results in the appearance of degenerative changes in the cells.

[Cellular ultrastructure of the meningococcus when incubated in a continuous culture of human FL-line amnion]. / Ul'trastruktura kletok meningokokka v usloviiakh inkubatsii ikh v perevivaemoi kul'ture amniona cheloveka linii FL.

Some details of the ultrastructure of several meningococcal strains having had contacts with cells in continuous human amnion cell culture FL for 6 hours to 2 days have been defined with greater precision by means of electron microscopy. The study has shown that the contact of meningococci with the tissue culture is accompanied by the appearance of meningococcal forms with the defective cell wall, similar to L-forms: spheroplast, protoplast, gigantic cells and microcells, as well as budding variants. The meningococcal variants with the defective cell wall, appearing in the cell culture, and the forms occurring (in different proportions) in "ripe" meningococcal populations developing in the culture media for a long time and isolated from a human body have been found to have no essential differences in their fine structure. These data indicate that any external influences (meningococci are highly sensitive to such influences) produce sufficiently rapid changes, similar to L-transformation, in the fine structure of these microorganisms.

[Interactions between Neisseria meningitidis and cell cultures (data of cytomorphologic studies)]. / Vzaimodeistvie Neisseria meningitidis s kul'turoi kletok po tsitomorfologicheskim nabliudeniiam.

The present work shows that the cytopathogenic action of N. meningitidis on continuous human amniotic epithelial cell culture FL begins from their active adhesion and subsequent invasion. The degree of the manifestation of the cytopathic effect depends on the capacity of the infective agent for adhesion and invasion and on its biological properties, as well as on the initial state of the cells. The infection of the cells is accompanied by disturbances in their mitotic activity together with the lesions of their chromosomal apparatus. The cells die either in the state of degenerative mitosis, or as the result of the rupture of the cytoplasm in massively invaded cells. The response of the cells to the invasion of faintly cytopathogenic and noncytopathogenic strains takes the form of nonprofessional phagocytosis.

[Characteristics of nonpathogenic Neisseria and Branhamella catarrhalis based on cytopathogenicity]. / Kharakteristika nepatogennykh neisserii i Branhamella catarrhalis po tsitopatogennosti.

The study of the action of 12 Neisseria species belonging to 112 strains, 6 B. catarrhalis strains and 202 meningococcal strains on the culture of continuous cell line F1 (human amniotic cells) has revealed that nonpathogenic Neisseria are essentially weaker than meningococci in their pathogenicity (expressed in terms of CPD50). Among nonpathogenic Neisseria highly cytopathogenic strains occur in 13.9% of cases, which gives grounds for considering them opportunistic bacteria. Sharply pronounced correlation between the adhesive and pathogenic properties of Neisseria has been observed. The cytopathogenic action of Neisseria is accompanied by the lesion of the chromosomal apparatus of mitotic infected cells.

[Dynamics of humoral immunity indices in patients with the generalized form of meningococcal infection]. / Dinamika pokazatelei gumoral'nogo immuniteta u bol'nykh s generalizovannoi formoi meningokokkovoi infektsii.

A possibility of using the passive hemagglutination test with meningococcus diagnostic agents of groups A and C for observing the changes in the infectious process was demonstrated. Sera of patients with generalized form of meningococcus infection showed an increase (by the 2nd--3rd week) and a rapid reduction (by the 4th week) of the specific antibodies titres to the levels seen during the first days of the disease. At the remote periods after the disease--in 2 to 5 years--hemagglutinins were revealed in the same titres as in healthy persons (1:10--1:13). Study of physico-chemical nature of antibodies demonstrated that at the early stages of meningococcus infection there formed antibodies referred chiefly to macroglobulins, and at the remote periods (after 3 months)--to microglobulins.