Gene trapping is one of the most promising technologies of vector mutagenesis used for discovery of genes active in embryogenesis. A brief description is provided for gene trapping based on the use of embryonic stem cells and vectors carrying the reporter gene lacZ without promoter, as well as the results obtained with the help of this technology. A total of four transgenic mouse lines were obtained, in three of which the vector was integrated into genes active during embryogenesis. As a result, various patterns of beta-galactosidase expression were observed in the limb rudiments, heart, liver, and other organs at different embryonic stages. At present, detailed studies of the site and time of action of the mutated genes in embryonic and postnatal development are under way, as well as molecular-genetic identification of these genes.

To elucidate feasibility of the use of autologous bone marrow stem cells in candidates to myocardial revascularization- patients with ischemic heart disease and cardiosclerosis after myocardial infarction.

The paper presents a retrospective analysis of long-term follow-ups (from 1959 to 2000) of 86 patients with acute pro-myelocytic leukemia, a rare type of hemoblastoses. The specific features of this form of leukemia is that blast cells of the bone marrow and peripheral blood have a specific granularity that plays a decisive role in the development of the severe hemorrhagic syndrome leading to patients' death. The morphological, cytochemical, cytogenetic, electron microscopic, and biochemical features of blast cells in this disease and its pathogenesis, clinical presentation, and treatment are considered. An extract from the records of a female patient who has had a complete clinical and hematological remission for 22 years is given. The follow-up of such a prolonged remission has not been covered in the Russian literature.

Genetic, physiological, and morphological studies of dwarf mutants of Arabidopsis thaliana (L.) Heynh. from the collection of the Department of Genetics and Breeding, Moscow State University, showed that the NA and LE genes are involved in regulating elongation of internode cells and sensitivity to various hormones. The na mutation suppressed stem growth only in the presence of the active LE gene. The absence of the LE activity (in the lele homozygote) restored stem growth of the na mutant to the level characteristic of the le-2 mutant, and a decrease in LE activity (in LEle heterozygote) almost completely suppressed the na phenotype. Phenotypic analysis of homozygous double mutants and heterozygotes obtained by crossing the na and le-2 mutants showed that the recessive le-2 allele has an epistatic effect on the semidominant na allele and that the genes possibly control consecutive steps of one biochemical pathway or one morphogenetic process. A hypothetical scheme was proposed for the interaction of the NA and LE gene products.

In the present work, we review the properties of some stem cell types, namely embryonic, hematopoietic and mesenchymal stem cells, which present the most significant interest for use in medicine. Stem cells are undifferentiated cells capable of both self-maintenance and differentiation into mature specialized cells. According to their origin, stem cells can be classified as embryonic and somatic ones. The first ones can be indefinitely maintained in culture, and possess the ability to differentiate into all cells of the adult organism. The second ones possess the limited capacity to differentiate and, probably, a limited proliferative potential. For therapeutic use, important but hotly debated is the plasticity of somatic stem cells, i.e. context-dependent differentiation into "non-related" cell types. It is assumed that the differentiation of the majority of stem cell types proceeds according to the principle of stepwise hierarchical maturation through the stage of intermediate rapidly proliferating progenitor cells. The use of stem cells in medicine is mostly at the preclinical stage now. Despite the fact that embryonic stem cells are highly promising as therapeutic agents, a number of circumstances substantially limits their therapeutic use in the near future. At the same time, approaches involving autotransplantation of hematopoietic or mesenchymal stem cells are beginning to be applied successfully in the clinical trials for treatment of limb ischaemia and myocardial infarction. It is clear that despite a large number of problems and unsolved questions, the use of stem cells in medicine promises a dramatic progress in the treatment of many severe diseases.

It has been systematized modern data on the myocardial regeneration and the regulation of cardiac cell proliferation in mammals and man. It has been performed an analysis published works which indicate that cardiomyocyte division and DNA synthesis in myocardial cells increase in many times during different pathological conditions. It has been generalized and analyzed results of experimental and clinical researches on the participation of stem cells in the regeneration of the heart. It has been present literature data on the telomeres and telomerase in cardiomyocytes.

To determine clinical significance of PRAME gene expression in multiple myeloma (MM) and feasibility of its use as a marker of residual tumor clone.

Using histological and morphometric methods, the peculiarities of sensomotor cortex morphogenesis were studied in rat fetuses subjected to fractionated gamma-irradiation in the period from 6th to 18th prenatal days in doses of 5, 25, 50 and 25-75 cGy. It that an Exposure to a fractionated radiation was found to negatively affect stem cell proliferation in the developing cortex and to increase the intensity of cell destruction in proportion to the radiation dose. The absolute number of macroglial cells was increased in all the cellular zones of developing cortex, that could be the result of both reactive stimulation of their production due to functional insufficiency, and of accelerated transformation of radial gliocytes into macroglia. Irradiation with the doses of 5-75 cGy caused the deceleration of neuroblast migration into the primary cortex, as indicated by the reduction of cell number in neural differon in the neocortical anlage and cell number growth in deeper layers of the developing cortex.

Genetically controlled proliferation and differentiation of stem nerve cells have been demonstrated to be among the repair mechanisms of the nervous system. Another such process is differentiation of neuroblasts from the cambial reserve.

The fertilized loach eggs were injected, before the beginning of cleavage, with the nuclear dye Hoechst 33258 and left to develop until the late blastula stage. Some cells of the dorsal area of stained blastoderm were transplanted in the analogous area of intact embryos of the same age, which led to an earlier and more pronounced development of head and trunk structures in recipients. A relationship was established between specific features of the development of recipients and localization of descendants of the transplanted cells. Transplantation of cells of the dorsal area of stained blastoderm in the ventral area of embryos of the same age led to the formation of two axial complexes, both at the same level of development, nut behind the control, and stained cells were located predominantly in one of twin embryos.

Light optic and electron microscopic studies were made of endomyocardial biopsies from the right ventricle of 8 patients who had undergone orthotopic transplantation of the heart 7-14 years ago. For this period rejection reaction was not typical, more marked were changes related to transplantation coronary disease and microcirculatory disorders: hibernation of cardiomyocytes (CMC), their apoptosis, interstitial fibrosis, dystrophic alterations of CMC. The results show the CMC pool may be resupplied with pluripotent (stem) cells as well as hibernating CMC which take part in the myocardial activity after myocardial circulation recovery by means of angioplasty and plasmapheresis.

An impact on the immune system is a principally new trend in optimizing the prevention and treatment of neonatal sepsis. The purpose of the case study was to investigate the clinical efficiency of neipogene. The study comprised 33 mature newborns with respiratory pathology and perinatal CNS lesion, who were at the artificial lung ventilation (ALV). Neipogene was found to increase for a short time period the absolute number of neutrophils, monocytes and the pool of stem cells (predecessors of the myeloid row) in peripheral blood, which cut the rate of sepsis, lethality, ALV time and treatment costs. The conclusion is that neipogene is safe and effective for the prevention and treatment of bacterial complications.

We studied the effect of Kropanol on local regulatory mechanisms of hemopoiesis during paradoxical sleep deprivation. The regulatory effect of Kropanol on granulomonocytopoiesis was determined by increased binding capacity of stromal cells in relation to granulocyte-macrophage precursors and increased formation of mixed hemopoietic islets leading to accelerated maturation of granulocyte-macrophage precursors and hyperplasia of the granulomonocytic hemopoietic stem. Stimulation of erythropoiesis with Kropanol was associated with increased formation of erythroid hemopoietic islets, accelerated differentiation of erythroid precursors, and high content of erythroid cells in the bone marrow. Kropanol increased proliferative activity of erythroid precursors. Stimulation of these processes depended on enhanced production of short-distance humoral regulators of erythro- and granulomonocytopoiesis.

The colonial internae of two decapod parasites Peltogasterella gracilis and Sacculina polygenea (Crustacea: Cirripedia: Rhizocephala) were studied in vitro by histological, and histochemical methods. We found stem cells, characterized by basophilic cytoplasm, a large nucleus and nucleolus, and a high alkaline phosphatase activity. The cytochemical manifestation of alkaline phosphatase activity in totipotent stem cells of the colonial rhizocephala is the first evidence of commonality in the functional characteristics of embryonic stem cells in vertebrate and invertebrate animals of such different taxa as the mammals and Crustacea.

There are accumulated evidences on existence of an imbalance between energy production and consumption in tissues in primary hypertension resulting in insufficient compensation of energy and its deficiency in cells (human essential hypertension, spontaneous hypertension in rats, SHR). An origin of these abnormalities resides in an alteration of cell mitochondrion ATP-synthetic function which ground is calcium overload of mitochondria due to increased cytosolic calcium redundantly entering into mitochondria and development of insufficiency of mPT pore removing calcium from matrix of the organells. There is an energy production deficiency in brain tissue of individuals with primary hypertension that is not initially caused by alteration of cerebral blood circulation of ischemic type. The mentioned energy abnormality is determined by decreased ability of brain mitochondria to synthesize ATP as a result of their calcium overload due to altered cell calcium handling in hypertension (so called membrane defect). In these conditions the registered normal or insignificantly changed cerebral blood flow in primary hypertension may be a result of systemic blood pressure increase in response to energy deficiency in brain tissue. Mechanisms mediating development of systemic hypertension include as the most important activation of vasomtor centers of brain stem. Other systems influencing vascular flow and peripheral resistance also contribute. Among those redundant (under conditions of calcium overload) production of oxidative radicals by mitochondria canceling vasorelaxing effect of NO should be specifically mentioned. The structural remodeling of peripheral circulation including rarefaction of capillary network provides for irreversibility of hypertension.