The structure and function of the chromosomal nucleolus organizer regions: the molecular, cytological and clinical aspects]

Numerous data concerning nucleolar organizer region (NOR) structure and function in normal and pathological human cells are analysed. The contents of argentophilic nucleolar proteins vary in the cells tested. The silver-stained test is closely connected with cellular proliferative potentials and differentiation status of the cells. This test also depends on the level of tumor cell malignancy and seemed to be very useful for megakaryocyte and cardiomyocyte studies. In summary, the NOR silver-staining approach is of great value for both fundamental cytological investigations and wide medical practice.     

Development and experience in the use of an immunoenzyme test system for determining specific antihemolysins in patients with measles

To determine the physico-chemical nature of specific antimeasles antihemolysins, an enzyme immunoassay (EIA) system with the use of stable measles virus hemolysing antigen has been developed. The expedient method has been worked out: the antigen diluted 1:20 with the initial hemolytic activity in the direct hemolysis inhibition test equal to 1:64 and, for its fixation, 0.1 M carbonate-bicarbonate buffer solution, pH 9.6, are used; the fixation of the antigen is carried out at 4 degrees C for 16-20 hours. The final dilution of the serum, whose coloration significantly differs from that of the control, is considered to be the titer of antimeasles antihemolysins. Specific antihemolysins belonging to three classes of immunoglobulins, A, M and G, are synthesized in measles. The detection of IgM-antihemolysins in high titers on the first day of rash opens prospects for using the newly developed EIA system for the rapid diagnosis of measles.     

Cytogenetic and virological characteristics of the initial line and clones of RH cells with various degrees of sensitivity to the tick-borne encephalitis virus

Virological and cytogenetic characterization of line RH and its two clones (RHk-20 and RHk-13/6), having different sensitivity to the tick-borne encephalitis virus (TBE), has been made. The RHk-13/6-cells are 10,000 times more sensitive to cytopathic effect of the tick-borne encephalitis virus in comparison with the RHk-20-cells. By its sensitivity to the virus the base line is in the intermediate position. Cytogenetic analysis revealed the variability interval decrease as to the chromosome number at cloning, and showed the structural stability of the line and clone karyotypes. The line RH and its clone K-20 have modal number of chromosomes equal to 65; the cell population with the chromosome number equal to 66 dominated in RHk-13/6. The application of methods of chromosome differential (G, C) staining and these for the detection of active nucleolar organizers (NO) permitted identifying the marker chromosomes and determining the difference between the clones and the line as associated with the presence of an additional homologue of chromosome 8 in the sensitive clone.