The role of the sympathetic nervous system in the regulation of bone marrow hematopoiesis has been studied on mice CBA after administration of 5-fluorouracil (114 mg/kg). The double injection (3-5 minutes before and 5 hours after 5 + U) of ganglionic blocking drug (pentamine, 6 mg/kg), alpha-adrenergic (dihydroergotamine, 3.9 mg/kg) or beta-adrenergic antagonists (propranolol, 5 mg/kg) inhibited the post-cytostatic reparation of erythro- and granulocytopoiesis. Besides, addition of the same neurotropic antagonists and 5-FU (10(-7) M) to bone marrow culture led to 1.5-3 fold decrease of cell content in comparison with alone cytostatic after 24 hours incubation. On the contrary injection of neuroblocking agents (twice in 5 hours) on day 3 after 5-FU administration elevated the total count of erythroid cells immature and mature granulocytic leukocytes in bone marrow and polymorphonuclear leukocytes in blood. Thus, the unequal role of the sympathetic nervous system in the regulation of hematopoiesis at the different periods after high dose of 5-FU administration has been demonstrated.

The effect of gas hypoxic mixture, containing 8% of O2 (GHM-8), on the ability of cell precursors of haemopoietic stroma (which form colonies (clones) of fibroblasts (CFU-F) in a culture, and are present in the bone marrow of adult rats) to repair potentially lethal and sublethal radiation damages has been investigated. The recovery of CFU-F from potentially lethal damages, that was studied after their delayed survival in a culture following irradiation of animals, proceeds at nearly the same rate in cells irradiated both in the air and in hypoxic conditions (GHM-8). Fractionated irradiation reduces the radioprotective effect of GHM-8 for CFU-F, particularly for the radioresistant subpopulation; the ability of CFU-F to recover from sublethal radiation damages decreases.

The ability of cell precursors of the haemopoietic stroma (CFU-F), that are present in the bone marrow of adult rats, to recover from potentially lethal and sublethal radiation damages has been investigated. The highest reparability, with respect to potentially lethal damages, is displayed by the most radioresistant CFU-F population, that forms loose colonies (clones) in a culture; the slope of the dose-response curve, not the extrapolation number, changes, and heterogeneity of the CFU-F population is observed. The results obtained confirm the presence of heterogeneity in the population of CFU-F, that was revealed in studying their radiosensitivity by the formation of dense and loose fibroblast colonies in a culture.

The cellular composition of peripheral blood, hematopoietic organs, and the content of erythroblastic islands of the red bone marrow revealed regular changes of concentrations of the RBCs, hemoglobin and reticulocytes thus corroborating the phenomenon of "early postnatal anemia" in rats. A considerable increase in number of the erythroblastic islands was revealed between the 10th and 45th days of life. Functional reconstruction of the islands in the postnatal ontogenesis was analysed in rats.

This article contain findings about effects of myelopid and taktivin to granulocyte-macrophage progenitor cells in rats. The method of bone marrow cultivation in diffusion chambers in vivo was used. It was shown that taktivin stimulates the cloning efficiency of granulocyte progenitor cells, and myelopid stimulates the cloning efficiency of fibroblastic colony forming units.

In this study we used the radiolabeled selective ligand (3H-NECA) of A2-types purine receptors in order to investigate specific NECA binding with human blood lymphocytes and bone marrow lymphoblasts. Relative affinity of 6-mercaptopurine and azathioprine for purine receptors was determined. One type of high affinity NECA binding sites have been shown on the lymphocytes (Kd = 0.57 mkM, Bmax = 0.63 pmol/10(6) cells), which selectively interacted with AZT, but not 6-MP. Relative potencies of substance in competitive radioassay: adenosine > AZT > 6-MP. Two classes NECA binding sites on the lymphoblasts have been identified. One of them corresponds to lymphocyte receptors. The second type of NECA binding sites is characterised by following parameters: Kd = 6.5 mkM and Bmax = 1.5 pmole/10(6) cells. They are selective sensitized to 6-MP. Relative affinity changes in the line: 6-MP > adenosine > AZT.

Data about the changes in the molecular organization of the cell nucleus on different levels of its structure during erythroid cell differentiation are presented. Changes are observed in DNA methylation and secondary structure. Protein composition of the chromatin and the length of the nucleosomal repeat change. Data about the peculiarities of the chromatin structure of erythroid-specific genes and their association to the nuclear skeleton are presented as well.

Age-specific trends in the number of early (CFUc-2 days) and late (CFUc-8 days) hemopoietic cell precursors were studied on the model of mature thymectomized (TE) mice. Bone marrow from TE mice derived at various postoperative intervals (4-100 weeks following thymectomy) was investigated against that from the control intact animals. It is shown that an increase in myelokaryocytes and absolute, but not relative, number of CFUc (CFUc-2 days and CFUc-8 days) was similar and age-related for both test and control animals. This fact evidences non-thymus-dependent regulation of CFUc content in the marrow. This conclusion can be also drawn from determination of CFUc sedimentation factor in the spleen of irradiated recipients. Lack of the thymus does not change CFUc ability to disseminate on the irradiated spleen.

The author studied the effect of the animal's age and marrow donor's thymectomy on differential potentials of CFUc by morphological structure of the splenic colonies. Bone marrow from thymectomized mice (TEM) was examined 1-25 months after thymectomy. Intact age-matched animals served control. The age of mice-donors had no influence on morphological types of the colonies formed by the marrow injected i. v. to irradiated recipients. TEM marrow developed all types of colonies known (erythroid, granulocytic, megakaryocytic, non-differentiated and mixed), though their percentage differs from the control. This is true for 11-day, but not for 8-day colonies. Among the 11-day colonies formed by TEM marrow the portion of megakaryocytes increased 3-fold, while mixed colonies were slow in formation when compared to the control.

An electroporation method has been used to introduce marker gene Neor into mouse stem hemopoietic cells which are capable of long-term hemopoiesis maintenance in marrow long-term cultures. Integration of the gene was tested by polymerase chain reaction. The effect of the procedure averaged 50-80% of marked CFUc. Electroporation did little damage to hemopoietic cell precursors. Gene transfer can be made most effectively using bone marrow from mice injected 5-fluorouracil 4 days prior to the experiment.

The results of a series of investigations on obtaining and analysing dominant temperature-sensitive lethals (DTS-lethals) are summarized. Using EMS, both cold- and heat sensitive mutations of this type were induced in large autosomes. The cold-sensitive mutations of chromosome 3 were revealed for the first time. The effect of genetic phone on DTS lethal penetrance and expressivity was studied. The character of expression of two mutations possessing a pleiotropic action was examined. The heat-sensitive 1(2)M90DTS mutation disturbed the structure of abdominal tergites in all imago and, besides, caused an abrupt decrease in the female reproductive period. The pattern of alterations observed in oogenesis along with the result of phenogenetic analysis suggest that this gene takes part in the genetic control over the proliferation of stem oogonial cells. The cold-sensitive 1(2)M66DCS mutation caused a number of disturbances in imago thoracic structures: inability to flight, raised up wings, extremity fracture, etc. Mutant flies showed serious disorders of indirect flight muscles both at morphological and at ultrastructural levels. It was established that this mutation was a cold-sensitive allele of Mhc gene which controls the synthesis of myosine heavy chains in drosophila.

Using the method of counting micronuclei it was shown that, in peripheral blood of larva of frog exposed to high doses of alkylating agent fotrin, the abundance of erythrocytes with signs of chromosomal aberrations significantly exceeds the level of spontaneous mutations on the 16th, 24th and 30th days of fixation but not on the 7th day following the experiment onset. In addition, with all terms of fixation under examination, an increased in comparison with norm number of binuclear erythrocytes was observed in the population of erythroid cells. Our observations combined with the data obtained by other authors confirm that amphibian hemopoietic cells can be used as a reliable test system for the detection of cyto- and genotoxic compounds as well as for the genetic monitoring of water environment.

An extract from regenerating calf spleen increases the survival rate of mice when injected after irradiation. The studies of the blood and immune systems characteristics at the subcellular, cellular and tissue levels have been shown that the preparation containing a complex of hemoregulating compounds modifies the processes responsible for radiation damage and repair.

In 67 patients with esophageal cancer, the peculiarities of endocrine regulation of alimentation after resection and plasty of the esophagus, using an isoperistaltic gastric tube were studied. Of these patients, 15 underwent correction of the disorders revealed. Accelerated evacuation of the content from a gastric transplant is accompanied by atony of the pylorus and is due to relative incompetence of neuroendocrine elements in gastric and duodenal mucosa (presence of a small amount of EC- and P-cells). Use of pentagastrin at the early postoperative period permits to accelerate the process of formation of the compensatory-adjusting mechanisms in the system of alimentation due to increase in functional activity of EC- and I-cells.

Cytomorphologic, morphometric and population analyses have revealed that during acute anemia, induced by phenylhydrazin, the proliferative activity of erythroblasts increases, an abrupt change in the structures of erythroid populations of both bone marrow and peripheral blood is observed, together with the increase in the rates of their specialization. Also, the ratio of the stem cells which differentiate by the erythroid pathway is increased, and the macro- and microcytosis mechanisms, which are essentially salient in normal conditions, are switched on. The roles of macro- and microcytes in the restoration of the normal amount of erythroid cells and haemoglobin contents in the blood are discussed.

Refractory anemia (RA) and RA with blast excess (RABE) showed inhibited proliferation of bone marrow erythroid cells (EC), the lowest values being in RABE. The latter, however, was accompanied with the highest count of PAS-positive EC, uneffective erythropoiesis being present in both RA and RABE. In sideroblast anemia the above proliferation was also inhibited, but uneffective erythropoiesis played much more pronounced role in pathogenesis of this anemia than in RA and RABE. The percentage of PAS-positive EC averaged 39.0%. The findings contribute to more profound understanding of anemia arising in myelodysplasia syndrome, to more accurate evaluation of therapeutic effect and prognosis in the above disease.

It is the conventional opinion that acquired aplastic anaemia is a heterogeneous disease including basically different conditions, such as idiopathic or virus induced pancytopenia, toxic-allergic marrow damage or autoimmunity. Here, an alternative concept is proposed, according to which aplastic anaemia is one disease, but multifactorial in all patients, apparent differences being due to the relative prevalence of one or the other pathological component in individual patients. Bone marrow from patients in the severe phase of aplastic anaemia does not grow in culture and is therefore not suitable for experimentation. Alternatively, bone marrow from patients who have resumed some degree of autologous bone marrow function, but still have residual signs of the disease after non-invasive therapy, offers the possibility to study pathological mechanisms in vitro. The majority of experiments presented have been done in such patients, assuming that their status of disease in some way reflects the original, more serious pretreatment condition. Three major pathophysiological components will be discussed, and it will be proposed how these factors act in concert to cause or aggravate aplasia.

Injection of prodigiozan to mice 24 h before irradiation caused, by the time of the radiation effect, a decrease in the number of haemopoietic cells-precursors (CFUs and CFU-HM) in the bone marrow and an increase in the functional activity of stromal cell-precursors--the haemopoietic microenvironment of transfer units (HMTU); in the spleen, the number of CFUs decreased, but the number of CFU-HM increased considerably. During the postirradiation period, the haemopoietic and stromal precursors were damaged to a lesser extent, and CFUs, CFU-HM and HMTU recovered more readily in prodigiozan-protected animals than in unprotected mice; the HMTU restoration preceded the increase in CFUs and CFU-HM levels.