[Status of the pediatric oncohematologic service in Russia]. / Sostoianie detskoi onkogematologicheskoi sluzhby v Rossii.

In spite of the fact that official statistical data show lower cancer morbidity of pediatric population in Russia than in Europe and USA (9.7 against 13.8 and 13.6, respectively), real cancer incidence may be close to mean incidence in Europe and USA as in Moscow it is 14.8 in boys and 12.0 in girls. Lower numbers in some other regions may be attributable to low standards of cancer diagnosis and inadequate case registration. In Moscow where standards of children's hematological service are high the proportion of some malignancies is the following: hemoblastoses-48.5%, CNS tumors-19.8%, neuroblastoma-8.0%, renal tumors-6.5%, sarcomas of soft tissues and bones-2.4 and 4.6%, respectively. The efficacy of anticancer treatment of children in many regions of Russia is poor, but the situation may be changed for the best by introduction of new approaches developed in the Moscow Research Institute of Pediatric Hematology.

[Cell composition of umbilical cord blood in complicated and uncomplicated pregnancy]. / Kletochnyi sostav pupovinnoi krovi pri patologicheskoi i neoslozhnennoi beremennosti.

Possible influence of most frequently encountered types of pathology during pregnancy on the cell composition of umbilical cord blood was studied. These pathologies included: treated iron-deficiency anemia, essential hypertension, threatening spontaneous abortion. A number and proliferative potential of granulocyte-macrophage precursor cells of umbilical cord blood were studied by agar drop-liquid media culture method. It was found that the types of pathology studied do not influence cell composition, number and proliferative potential of granulocyte-macrophage precursor cells from umbilical cord blood. These results show that umbilical cord blood after pathological pregnancy can be considered as a source of transplantable hemopoietic cells.

[Distribution of hematopoietic stem cells in the mononuclear fraction of human umbilical cord blood]. / Analiz raspredeleniia gemopoéticheskikh stvolovykh kletok v mononuklearnoi fraktsii pupovinnoi krovi cheloveka.

The advances in transplantation of hemopoietic stem cells (HSC) from umbilical human blood (UHB) necessitate introduction of effective methods of HSC isolation and preservation. The studies show that UHB cells remained viable even after several days of storage at room temperature. Density gradients proved effective for isolation of cell precursors from UHB. Most of hemopoietic cell-precursors in UHB have low density (under 1.070 g/ml) which becomes greater with cell maturation.

[Regulation of proliferation of stromal fibroblasts with methylprednisolone in cultures in vitro]. / Reguliatsiia proliferatsii stromal'nykh fibroblastov metilprednizolonom v kul'turakh in vitro.

The effect of methylprednisolone [MP) in the concentration 10(-7) M on cloning capacity and proliferative potential of splenic and medullary stromal fibroblast precursors was studied in hematologically normal children. Medullary fibroblast culturing was performed according to A. Ya. Fridenstein method, splenic fibroblast culturing by an original procedure proposed by the authors. MP stimulated proliferation of human marrow clonogenic fibroblasts more profoundly than a xenogenic feeder could do. A successive introduction of MP and the feeder gives no rise to synergism, while their simultaneous application induces a blocking effect. Basing on these findings it is suggested that MP and the feeder compete for the same receptors on the adhesive cells of the explant. Splenic fibroblasts proved sensitive to neither xenogenic feeder nor to MP in concentration 10(-7) M.

[The effect of polychemotherapy on hemopoiesis in acute lymphoblastic leukemia in children]. / Vlianie polikhimioterapii na gemopoéz pri ostrom limfoblastnom leikoze u detei.

Bone marrow granulocytic-macrophagal precursors (GMP) and fibroblastic precursors (FP) were measured in 235 children with acute lymphoblastic leukemia (ALL) receiving polychemotherapy (PCT) in progression of the disease. A total of 408 culture investigations were conducted. PCT proved to exert different effects on hemopoiesis during the first acute ALL period and remission. In the former period the target for PCT were blast cells, the course of induction therapy increased the number of GMP, FP and early granulocytic cells. In recurrent ALL the sensitivity of GMP to PCT grew, while FP remained intact. PCT performed in remission resulted in gradual suppression of granulocytopoiesis, GMP beginning from the second remission year. The treatment discontinuation on remission year 3-5 produced enhancement of granulocytosis by all parameters.

[Characteristics of pathogenesis of acute leukemia in children]. / Osobennosti patogeneza ostrykh leikozov u detei.

The main components of acute leukemia pathogenesis have been considered from the current positions: origination of the leukemic clone, characteristics of leukemia tumor histogenesis, mechanisms of proliferation and differentiation of leukemic cells. The main pathogenetic differences of acute leukemia in children and adults have been traced. The importance of these differences for the clinical picture, prognosis and response to chemotherapy has been analyzed.

[Stromal fibroblasts of normal bone marrow in children]. / Stromal'nye fibroblasty normal'nogo kostnogo mozga u detei.

Reference values of the number and proliferation index (PI) of stromal fibroblasts in children have been presented: CFUf per 10(5) = 57.0 +/- 4.1; CFUf in 1 microliters = 85.4 +/- 8.1; PI = 1.7 +/- 0.05. It has been shown that the number of stromal fibroblasts increases in the prepubertal period, especially in girls. No relationship has been observed between CFUf and the number of platelets and megakaryocytes in the children investigated. Correlation has been established between the number of bone marrow clonogenic fibroblasts and the amount of myelokaryocytes and the number of granulocytic-macrophagal precursors in the bone marrow.

[Biological principles of the therapy of acute leukemia]. / Biologicheskie osnovy terapii ostrykh leikozov.

The biological features specific to the tumor growth in acute leukemia are responsible for the disease prognosis and its response to polychemotherapy. Current molecular-biological, karyological, cytological, kinetic, and culture investigation techniques have contributed much to the understanding of the pathogenesis of acute leukemia and may be used as a guide to appropriate disease management.

[The dependence of the clonogenic fibroblast proliferation of human bone marrow on the feeder]. / Zavisimost' proliferatsii klonogennykh fibroblastov kostnogo mozga cheloveka ot fidera.

The proliferation of human bone marrow stromal fibroblasts depends on the growth factors. Xenogenic bone marrow cells, previously radiated in a dose of 3000 Gy, are shown to be a source of such factors. The human bone marrow cells contain both stimulators and inhibitors of the fibroblast proliferation. The inhibitory activity of the bone marrow cells increases with their concentration in explants. The optimal culture conditions are developed. The efficiency values of the fibroblast cloning in children and adults are presented and compared.

[Granulocytopoiesis in acute lymphoblastic leukemia in children]. / Granulotsitopoéz pri ostrom limfoblastnom leikoze u detei.

The number, proliferative potential and differentiation potentialities of bone marrow granulocytic-macrophagal precursors were investigated in 130 ALL patients (77 children in the acute period of disease, 53 children in remission) and in the bone marrow of 65 controls without hematologic pathology. A decrease in the number of clonogenic precursors was observed in all stages of acute lymphoblastic leukemia, the decrease being particularly marked in the acute period of disease characterized by substantial bone marrow infiltration by leukemic cells. A decrease in the number of precursors and their proliferative potential was shown to be associated with the influence of leukemic blasts. In remission the numerical reduction of the precursor pool was determined by a cytostatic therapeutic effect. The ability to differentiation of granulocytic and macrophagal clonogenic precursors in ALL children was unchanged.