[Regulation of erythropoiesis in patients with iron deficiency anemia].

Erythropoietin level in the blood plasma, iron metabolism, and some erythron parameters characterizing anemia expression, erythropoiesis effectiveness and processes of hemoglobin synthesis were studied in patients with iron-deficiency anemia (IDA). The results of the investigation helped the authors to establish that hormone production in IDA patients is under the control of a feedback mechanism that is functioning at a lower level as compared to other non-renal anemias. It has been suggested that optimum possible erythron functioning in IDA patients is achieved under these conditions.

[Results of hematological examinations of crew members of the space vehicles EO-2, EO-3 and EO-4].

The authors' opinion that adaptation inhibition of erythron functioning under weightlessness produces an unfavourable effect on the optimal physical state of a cosmonaut and his working capacity in the post-flight period has been confirmed by the analysis of certain hematological parameters studied in cosmonauts. The data obtained have necessitated investigation of threshold values of erythron functioning under weightlessness, and creation of artificial gravitation on board the piloted space ship to normalize erythropoiesis. Investigation of these problems of space hematology would be helpful in validation of the limits of human's long-term stay under weightlessness, and in the pre- and post-flight period management.

[The spatial-temporal organization of erythropoiesis in exposure of the body to hyperbaric oxygenation].

A systemic approach to appraisal of the mechanisms of changes of erythropoiesis biorhythms in stress is suggested. The authors studied the daily and seasonal rhythms of serum erythropoietin (EP) level, the production of erythrocytes (PE), the kinetics of bone marrow erythroid cells, and the activity of lipid peroxidation (LPO) and G-6-PDG in peripheral blood erythrocytes in albino rats. As a stress factor hyperbaric oxygenation initiated LPO acceleration and change of PE circadian rhythm with mesor decrease.

[Erythropoietin in differential diagnosis of erythremia and secondary erythrocytosis].

The results of estimating blood plasma erythropoietic activity in patients with polycythemia of unclear genesis, in 95% of cases coincided with the clinical diagnosis proved during further follow up. These data have permitted recommendation of estimating blood plasma erythropoietic activity in patients to verify the diagnosis of polycythemic states.

[Erythropoiesis inhibitor in the plasma of patients with hemopoietic dysplasias].

Altogether 21 patients were examined for an erythropoiesis inhibitor contained by the IgG fraction of the blood plasma. All these patients suffered from hemopoiesis depression. The inhibitor identified in the immunoglobulin fraction of the blood plasma of 40% of the patients manifested itself at the stage of erythroid precursors of bone marrow cells.

[Humoral regulators of erythropoiesis during the body's adaptation to chronic respiratory insufficiency].

It was revealed during examination of 91 patients with chronic nonspecific lung diseases for the blood titers of erythropoietin, erythrocytic chalones, erythrocyte hemolysis products and medium molecules that in the stage I respiratory failure, there were no material changes in the titres of erythrocyte hemolysis products, erythropoietin and medium molecules, whereas the titer of erythrocytic chalones appeared to be high. Stage III of the disease was also marked by no changes in the titer of erythrocyte hemolysis products. However, the titers of erythropoietin and medium molecules rose whereas the titer of erythrocytic chalones was reduced.

[The mechanisms of the development of erythrocytosis during adaptation to dynamic muscle loads].

Dynamic muscular exercises intensified the erythropoiesis within one week and the erythrocytosis within two weeks in rats. An increase in the marrow erythroid cells proliferative activity was the basis of this reaction. The dynamics of this index coincide with the blood reticulocyte concentration dynamics.

[Erythron in patients with polycythemia vera during treatment by erythrocytapheresis and bloodletting].

An analysis of the results of determination of erythropoietin in the blood plasma of patients with polycythemia vera and data on the kinetics of erythroid cell proliferation led to a conclusion that erythrocytapheresis more than bloodletting stimulated the production of erythropoietin and the cell proliferative potential. Activation of regenerative processes probably determined by deinhibition of the normal clone of bone marrow erythroid cells, can account for the mechanism of a therapeutic effect of erythrocytapheresis in patients with polycythemia vera.

[Effect of medium-sized molecules fro uremic serum on hemopoiesis in intact mice].

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.

[Concentration of middle-sized molecules in the blood of children with chronic renal failure during treatment with short-term hemodialysis].

Blood serum from children and young patients with chronic kidney insufficiency at the terminal step as well as from healthy donors was fractionated using ultrafilters "Amicon" XM-50 and Sephadex G-25. Three fractions were obtained: F1--molecular mass 50,000-5,000, F3--3,000-800 (fraction of middle mass molecules, MM) and F5 < 200. Amount of protein in the MM fraction exceeded 7-10-fold the protein content in the same fraction of donor blood serum.

[Effect of uremic serum and its fractions on stem cells 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.

On the inhibitory effect of the serum of uraemic children on erythropoiesis.

The erythropoietin activity and the erythropoiesis inhibiting factor(s) (EIF) were studied in the serum of 10 children and adolescents suffering from terminal renal insufficiency. The influence of haemodialysis on these factors was examined as well. As a test model for the estimation of erythropoietin activity and EIF we used hypertransfused polycythaemic mice.

[Erythropoietin and erythropoiesis inhibition factor in the newborn and infants with cyanotic heart abnormalities].

In the present study, hematocrit, pO2 in the capillary blood, reticulocyte count, erythropoietin activity in plasma and activity of the erythropoiesis inhibition factor in 24-h collective urine were determined in newborns and infants with cyanotic malformations of the heart (transpositions of the big arteries). The plasma of the healthy newborns shows immediately after birth an erythropoietin activity below 1%, as measured by the 59Fe incorporation. The erythropoietin activity of the plasma of infants with cyanotic malformations of the heart is enhanced up to the 14th day of life.