[Spontaneous death of mononuclear cells, obtained from health donors and patients with systemic lupus erythematosus].

Unstimulated human peripheral blood mononuclear cells (MNC) underwent death during incubation in vitro. According to morphological criteria the type of death was identified as apoptosis. There was a good correlation between a fraction of apoptotic cells qualified morphologically, and fraction of "apoptotic" comets.

[Dna comets as markers of cells death].

Unstimulated human peripheral blood lymphocytes gradually underwent death during incubation in vitro. According to morphological criteria, the type of death was identified as apoptosis. After immobilization in agarose, lysis, and electrophoresis, these lymphocytes formed DNA comets, which differed in DNA content, tail length, tail moment, and the fraction of DNA migrating in the comet tail.

[Mechanism of radiation death of human peripheral blood lymphocytes, assessed by the DNA-comet method].

Radiation-induced death of human peripheral blood lymphocytes (HPBL) was studied using the comet assay. It has been shown that gamma-irradiation induced simultaneously two forms of death, necrosis and apoptosis which may be discriminated by the comet assay. Three groups of comets formed by HPBL are specified: symmetric/slowly asymmetric comets attributed to viable cells (C0/C1-class of comets); comets reminding "tear-drop" (C3/C4-class of comets) which are characterized by decreased total fluorescence of comet and formed by dying/dead (necrotic or apoptotic) cells; intermediate form of comets (C2-class), containing head, tail and attributed to cells committed to apoptosis (containing high molecular weight fragments of DNA).