Interleukin-1 beta is an irradiation-induced stromal growth factor.

Gamma irradiation of tissues and organs leads to many pathological consequences due to the formation of reactive oxygen species, DNA damage and the subsequent massive death of cells. The therapeutic use of gamma irradiation in the treatment of cancer is based on its penetrating power and damaging effects on tumor cells. Other effects from the irradiation are unnoticeable in comparison.

VCAM-1 expression on bone marrow stromal cells from patients with myelodysplastic syndromes.

We studied the expression of VCAM-1 adhesion molecules on stromal cells from the bone marrow of patients with myelodysplastic syndromes, healthy donors, and patients with chronic myeloproliferative diseases and acute leukemias. Expression of adhesion molecule on mesenchymal stromal cells from the bone marrow of patients and healthy donors was evaluated after 2-4 passages by the methods of immunoprecipitation and electrophoresis. VCAM-1 expression in the majority of patients with myelodysplastic syndromes was lower than in healthy donors.

Expression of cathepsin L and its endogenous inhibitors in immortal and transformed fibroblasts.

Methods: The activities of cathepsin L and its endogenous inhibitors were analyzed in rat embryo fibroblasts, immortalized and transformed by different genes.

Results: Regardless of the transfecting agent used (DNA of adenovirus SA7 or polyomavirus LT gene), the immortal cells showed an increase in the cathepsin L activity (in both lysates and conditioned media) compared to primary fibroblasts. Transformed cells exhibited either an increase (with c-Ha-ras gene) or decrease (with E7 HPV gene) in cathepsin L activity in lysates as opposed to immortal cells.

[Limited proteolysis of integrin alpha v beta3 from human placenta].

Purification of alpha v beta 3 integrin from human placenta with successive usage of two affinity sorbents--immobilized monoclonal antibodies to alpha v beta 3 integrin and immobilized RGD-containing decapeptide allowed to purify this integrin's partially degraded fraction, that was nevertheless able to interact with its ligand. During the incubation of partially degraded alpha v beta 3 integrin at 37 degrees C its further degradation went on. Addition of serine proteinase inhibitors: (phenylmethilsulfonyl fluoride, leupeptin and aprotinin) completely suppressed integrin further degradation of alpha v beta 3.

[Aminopeptidases in human leukemia cells].

Aminopeptidase activity in lymphoid cells of patients with various lymphoproliferative diseases was studied. The enzyme activity was detected in lysates of all leukemic B- and T-cells. The lymphoid cells contained aminopeptidases of at least two classes: metallo- and SH-dependent enzymes.