Experimental evaluation of rat cord blood as a source of stem cells stimulating regeneration of the bone tissue.

We studied subpopulation structure of rat cord blood and its effects on regeneration of the bone tissue. In cord blood leukocytes, cell fractions with phenotypes CD45+/CD90-, CD45-/CD90+, CD34+/CD45+ were determined. The cells adhered to plastic during culturing and had a fibroblast-like morphology.

Opposite effects of 5-hydroxymethyluracil on mitogenic response of T cells stimulated through T-cell receptor or through T-cell receptor and CD28 co-receptor molecule.

The effect of a synthetic analog of "minor" pyrimidine base 5-hydroxymethyluracil (0.01-10 μg/ml) on the mitogenic response of donor peripheral blood T cells was studied in vitro under conditions of lymphocyte stimulation through T-cell receptor (antiCD3 monoclonal antibodies) or through T-cell receptor and CD28 co-receptor molecule (antiCD3 and antiCD28 monoclonal antibodies). 5-hydroxymethyluracil suppressed the mitogenic response of T cells stimulated with antiCD3 antibodies, which was paralleled by an increase in the count of silent cells and decrease in the count of dividing lymphocytes, but not by stimulation of apoptosis of activated cells.

Sensitization of the thymus to hypoplastic effect of glucocorticoids after long-term hypokinetic stress.

Long-term hypokinesia increases sensitivity of the thymus to the hypoplastic effect of glucocorticoid preparation triamcinolone acetonide by potentiating the proapoptotic effect of the glucocorticoid.

Activation of apoptosis as a mechanism of thymus involution during repeated immobilization.

Lymphopenia preceded involution of the thymus during daily immobilization for 1 h. Hypoplasia of the thymus was associated with induction of apoptosis.

Lymphocyte Apoptosis during Hemorragic Fever with Renal Syndrome.

Programmed cell death (PCD) is a fundamental process regulating immune homeostasis. During acute viral infections PCD of lymphocytes by apoptosis is necessary for removing the excess of activated antigen-reactive T cells and down-regulation of the immune response. On the other hand, apoptosis is the key mechanism of elimination of viral-infected cells.