In CBA mice calibrated stenosis of the portal vein was produced. Liver and immunocompetent organs were morphologically analyzed. The total number of hemopoietic stem cells in the bone marrow was estimated by the colony-forming cells and in the spleen after immunization with sheep red cells by the plaque forming method. It is established that stenosis of the portal vein (on the average by 45% and 58%) produced the histostructural changes in the liver and in the immunocompetent organs. Expression of morphological changes depended on the time elapsed after operation and the degree of the portal vein stenosis. These changes were the most pronounced on the 16-17th day when stenosis of the portal vein was 58%. The character of the changes in the number of the hemopoietic stem cells in the bone marrow and in that of antibody-forming cells in the spleen depended on the degree of the liver damage. These changes increased with the degree of the liver histostructure damage. The maximal liver damage was accompanied by a decrease of these indices.

The role of T-lymphocytes in regulation of proliferation and differentiation processes of committed myelopoiesis cell precursors in F1 (CBA-C57Bl/6) mice, treated by 10-hour immobilization was studied. One of the first reactions of hemopoietic precursors at stress was estimated to be the increase of active proliferating cells-precursors, accompanied by the quantitative changes of their content. The creation of T-cell deficit by means of anti-thymic serum resulted in abolition of the above mentioned changes of erythroid and granulo-macrophage precursors marked in the processes of adaptation syndrome development.

CFU-f-derived stromal colony formation was accomplished in adherent marrow cell cultures (AMCC) with serum-rich medium. It turned out to require additional stimulation by hemopoietic feeder cells: by irradiated marrow cells and spleen cells if they possess megakaryocytes and platelets or by platelets from the blood. PDGF, EGF and IL-3 did not substitute the colony stimulating activity of feeder cells. Thymus, lymph node cells and blood leucocytes had no colony stimulating activity. At low oxygen concentrations which improve colony formation the stimulating activity of hemopoietic feeder cells was expressed, as well. Thus, CFU-f colony formation depends on stimulation by hemopoietic cells in addition to serum growth factors. In full populations of marrow cells the CFU-f colony formation is stimulated by marrow cells which accompany the CFU-f.

In 24 hours adherent marrow cell cultures (AMCC) were represented by single stretched fibroblasts. In non-feeder-supplemented AMCC most of the CFU-f remained single fibroblasts or passed through 1-3 cell doublings [correction of dudlings]. The colony stimulating activity of irradiated marrow cells was found to be diffuse across the Millipore filter, which seems to indicate that haemopoietic marrow cells produce a colony stimulating factor which is required for triggering the CFU-f from the Go-period of the cell cycle into cell proliferation.

Comparative study of morphological structure of chromosomes in different hematogenous cells of experimental white rats was carried out on the 5th day after ablation of spleen, on the 6th day after intermittent action of hypoxia in an altitude chamber and on the 6th day in case of aseptic inflammation after introduction of turpentine. In the populations of marrow cells of all experimental animals three types of chromosome sets were detected, their ratio changing, due to the regulation level of different hematogenous rows.

The concentration of hemopoiesis restoring units (HRU) in bone marrow of mice was assayed by using the limiting dilution method in transplantation to lethally irradiated mice. 7 to 12.7 HRU were found in 10(6) bone marrow cells of CBF1 mice and 19.2 to 50.6 HRU in BCT6F1 mice when the survival of the recipients was registered in 4 weeks after transplantation. The proportion of not surviving recipients increased with time when marrow doses were low (2.5 X 10(4) to 2 X 10(5) cells or 0.5-2.5 HRU per mouse) and remained stable when middle or high marrow doses (10(6)-10(7) cells) were used.

Hemopoietic bone marrow stem cells (CFCs) of young (3-5 months) and old (23-24 months) were studied according to their ability to form colonies in spleens of the lethally irradiated animals. The number, morphology and volume of CFCs were microscopically examined. The content of CFCs remained unchanged during aging. The number of erythroid colonies decreased in old mice, while that of granulocyte-macrophage and mixed colonies did not change. The megakaryocyte colonies showed even an increase with age. Volumes of all the colony types, except megakaryocyte, reduced. The results obtained thus reflect some age-related features of early stages of the stem-cell differentiation.

The mechanisms of thymic involution with age are analyzed in terms of both intrinsic and extrinsic aspects. The intrinsic factors include: decrease in the number of thymocyte-precursors (pro-T cells) in the bone marrow, in emigration of pro-T cells into the thymus, in proliferation of thymic lymphocytes and decrease in extrathymic factors promoting proliferation of thymic lymphocytes. The extrinsic factors capable to exert modulating effects on the thymic function are humoral factors of the hypothalamic-pituitary origin. It seems much easier to manipulate the extrinsic factors by controlling neuro-endocrine stimulation, and to restore the thymic involution. This is quite encouraging, because it permits restoring the impaired immune functions of the aged people.

The influence of ionizing radiation (5 Gy) on the interleukin-2 inhibitor in mouse serum has been investigated. It has been shown that the concentration of IL-2 inhibitor decreases on days 3-6 and increases considerably on days 10-15 after irradiation. A correlation has been found between the number of T-helpers in spleens of exposed allogenic chimeras and low IL-2 inhibitor content of serum. An attempt has been made to use the increased IL-2 inhibitor level for improving the acceptance of allogenic cells in the sublethally exposed mice.

Experiments on mice (CBA X C57 Bl6)F1 using endo- and exogenous cloning have shown that ultraviolet irradiation of blood enhances colony stimulating properties of plasma. Stimulation of colony formation occurs both in vitro, on direct contact of UV-irradiated blood plasma with bone marrow cells, and in vivo, upon this injection to the whole organism. In the latter case, increased migration of colony forming hematopoietic cells from the bone marrow can be noted. Single intravenous injection of syngenic UV-irradiated blood prevents inhibition of hematopoietic function of the bone marrow induced by closed brain injury.

The syngeneic thymocytes increase the efficiency of spleen colony formation and proliferative activity of CFU-S derived from fetal liver on 13th-16th day of gestation and CFU-S from long term bone marrow culture. The thymocytes effect spleen colony cells. These data indicate that T-cell-CFU-S interaction in spleen colony formation have a physiological character.

In 23 patients with a severe cranial-cerebral trauma the operative material (pieces of the cortex, obtained from the destructive, transitional and relatively preserved zones in the bruise foci with crushing, localized in various lobules of the cerebral hemispheres) has been studied. From 2 h up to 9 days after trauma, changes, characterizing the state of the vascular bed, nervous and glial cells have been followed. In the external area of the transitional zone in 15 patients and in the relatively preserved zone in all the patients reversibly altered nervous cells predominate. Only in the destructive zone in all 23 patients and in the whole transitional zone in 8 patients neurons in all cortical layers are deeply injured and unviable. Certain considerations on differential surgical tactics, when treating the bruise foci with crushing at a severe cranial and cerebral trauma are presented.

It was shown that asterin, a higher plant preparation, had a marked antiblastomic action and a favourable effect on differentiation of the precursor cells and blood cells. It accelerated proliferation, migration of the truncal hemopoietic cells and their transfer from the dormant state into the cellular cycle. It also changed the cell differentiation in the direction of myelopoiesis. The mechanism of the asterin's immunomodulating action was found to be associated with regulation of T-cellular immunity and T-dependent immune response.

Hypothesis is proposed that the human brain has the sensory system (ecoceptive sensory system) which responds to changes of the Earth electromagnetic fields (EEFs) and meteorologic factors (MFs). Acupuncture points which are activated easily by adequate somatosensory stimuli (mechanical, temperature) and electromagnetic fields (electropuncture, magnetopuncture) can be polymodal receptors of the ecoceptive sensory system. It is supposed that the sensory endings of acupuncture points are excited by sharp changes ef EEFs and MFs. Through the neuronal brain stem structures, especially through hypothalamus, acupuncture points excitation starts the adaptive mechanisms intended to compensate the brain functional systems deviations, provoked by prolonged EEFs and unsettled weather environmental influences.

Role of the stromal microenvironment in regulation of bone marrow hemopoiesis at the administration of the thrombocyte disaggregant curantyl was studied by the method of heterotopic transplantation of the mice bone marrow. It is shown that the action of curantyl on hemopoiesis is realised through the stem stromal cells of the bone marrow. It is noted that the inhibitory action of the preparation on proliferation of osteogenic precursor-cells is followed by activation of bone resorption processes in regenerating ectopic hemopoietic organ. Under the action of curantyl at low bone marrow cellularity in the focus of heterotopic hemopoiesis and femur an increase of mitotic activity in hemopoietic elements is noted. It is revealed that a phenomenon of ineffective megakaryocytopoiesis with intramedullary destruction of megakaryocytes leads to the local excretion of the thrombocyte released growth factor (TRGF) which has a compensatory character.

Cultivation of human bone marrow cells in plasma clot resulted in high efficiency of cloning. It probably results from additional thrombin stimulus on fibroblast-cell proliferation. Another cause of high cloning efficiency is independent of adherence to culture flask surface. Plasma clot system permits clearcut morphological examination. Plasma clot system is in superiority to other culture systems. In this culture system several types of stromal-hemopoietic cells interactions were found, which probably correlate to in vivo interaction of these cells.

Acute experimental hepatitis was induced by a single injection of 1% water solution of allyl spirit in a dose of 100 mg/kg. Morphofunctional state of peripheral blood and bone marrow cells was studied with the use of hematological and cytochemical methods. Specific changes were detected in the peripheral blood and bone marrow cell parameters in the early (6 and 12 h) and late (24h--10 days) periods after the injection. Changes in the liver and in the blood and bone marrow cells were irreversible. Most of the parameters studied returned to normal 22 days after the injection of allyl spirit.