[Effect of medium-sized molecules fro uremic serum on hemopoiesis in intact mice]. / Vliianie "srednykh molekul" uremicheskoi syvorotki na krovetvorenie intaktnykh myshei.

The effect of a medium-sized molecular fraction (3000--800) isolated from serum of patients with chronic renal insufficiency on erythropoiesis in intact mice was studied. The fraction significantly lowered the erythropoietic count of the bone marrow (maximum by 47%). The absolute number of myelocytes ranged within normal. The number of granulocytopoietic and lymphoid cells remained statistically unchanged throughout the whole experiment. The results indicate that the medium-sized molecular fraction displays activity in the stage of erythroid precursors.

[Effect of uremic serum and its fractions on stem cells in vivo]. / Izuchenie éffekta uremicheskoi syvorotki i ee fraktsii na stvolovuiu kletku in vivo.

Serum of 18 children and adolescents with chronic renal failure at the terminal stage of the kidney disease was fractionated on plates manufactured by Amicon Company and on Sephadex G-25. Uremic serum and ultrafiltrate with a molecular mass of 50,000 produced erythropoiesis inhibiting effect in polycythemic mice. However, the uremic serum and its fractions (50000--5000 and 3000--800) did not alter the number of microscopically visible colonies in the spleen of irradiated mice and their differentiation and proliferation compared to the mice that had received donor serum. Thus the inhibitory effect of serum and its fractions of patients with chronic renal failure is possible effected at the level of undifferentiated erythroid precursors producing no effect on the pluripotent stem cell.