Effect of combined administration of estradiol and progesterone on the mitotic cycle of the epithelial tissues of the reproductive tract of ovariectomized white rats

The duration of stages of the cell cycle in the uterine and vaginal tissues of ovariectomized rats, treated with estradiol and estradiol-progesterone, was estimated using the labeled mitosis method. The joint treatment shortened G2 period in epithelial tissues. In the uterine epithelial tissues of estradiol-progesterone treated rats, the duration of S period was prolonged. In all tissues, progesterone stimulated the entry of cells into a second round of DNA synthesis. The estrogen-gestagen treatment inhibited the movement of vaginal epithelial cells from basal to superficial layers.     

Copper resistance in Desulfovibrio strain R2

A sulfate-reducing bacterium, designated as strain R2, was isolated from wastewater of a ball-bearing manufacturing facility in Tomsk, Western Siberia. This isolate was resistant up to 800 mg Cu/l in the growth medium. By comparison, Cu-resistance of reference cultures of sulfate-reducing bacteria ranged from 50 to 75 mg Cu/l. Growth experiments with strain R2 showed that Cu was an essential trace element and, on one hand, enhanced growth at concentrations up to 10 mg/l but, on the other hand, the growth rate decreased and lag-period extended at copper concentrations of >50 mg/l. Phenotypic characteristics and a 1078 bp nucleotide sequence of the 16S rDNA placed strain R2 within the genus Desulfovibrio. Desulfovibrio R2 carried at least one plasmid of approximately of 23.1 kbp. A 636 bp fragment ot the pcoR gene of the pco operon that encodes Cu resistance was amplified by PCR from plasmid DNA of strain R2. The pco genes are involved in Cu-resistance in some enteric and aerobic soil bacteria. Desulfovibrio R2 is a prospective strain for bioremediation purposes and for developing a homologous system for transformation of Cu-resistance in sulfate-reducing bacteria. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effect of estrone on formation of the focus of heterotopic hematopoiesis

The effect of estrone injections on the heterotopic bone marrow organ formation was studied in (C57Bl X CBA)F1 mice by bone marrow shaft transplantation under the kidney capsule. Estrone injections resulted in femur marrow fibrosis, the increase in the weight of femur and heterotopic organ ossicle, drastic reduction in heterotopic organ cellularity. Depression of hemopoiesis in ectopic organ cannot be attributed to mechanical displacement of hemopoietic cells because a newly formed bone cavity under the kidney capsule was not closed. Thus, estrone had a detrimental effect on the creation of microenvironment in the heterotopic organ.     

The action of dipyridamole on megakaryocytopoiesis in regenerating and stationary bone marrow cell populations]

The effect of dipyridamole on megakaryocytopoiesis in regenerating and stationary populations of mouse bone marrow cells has been studied by heterotopic transplantation of the bone marrow using histological, electron microscopic and biochemical techniques. It is shown that drug administration induced destruction of megakaryocytes. In megakaryocytic cytoplasm giant lipid granules were found whose growth and number increase resulted in megakaryocytes kill. Gas-liquid chromatography was used to evaluate the effect of dipyridamole on distribution of lipid fatty acids of the stationary and regenerating populations of the bone marrow cells. A marked increase of the percentage of docosahexaenoic acid was found in lipids of the stationary population. Chronic dipyridamole administration caused an increase of percentage of myristic, palmitic oleic acids, and decrease of percentage of arachidonic and eicosapentaenoic acids in lipids of regenerating bone marrow cells population.     

The role of the thymus in regulating the stromal cells responsible for the transfer of the hemopoiesis-inducing microenvironment in stress

The role of thymus in the regulation of stromal elements, responsible for haemopoiesis inducing microsurrounding transfer of animals, subjected to 10-hours immobilization, was studied. The development of bone marrow hyperplasia and stimulation of functional activity of stromal cells, responsible for haemopoiesis inducing microsurrounding transfer, were shown to be thymus dependent processes during stress.     

Effect of dipyridamole on the interrelations of the stromal and hematopoietic tissues of the bone marrow in experimental studies]

By means of heterotopic transplantation of the bone marrow interrelations of the stromal and hemopoietic tissues of the mice bone marrow have been studied at administration of dipiridamol. Effect of the drug to the hemopoiesis is realized via stem stromal cells of the bone marrow. Under the influence of dipiridamol a focus of heterotopic hemopoiesis the osteogenic component in it is present only in 30% of cases in comparison with the control. Inhibition of the stromal component proliferation is accompanied with increasing mitotic activity of the hemopoietic elements against the background of the bone marrow cellularity decrease both in the femoral bone and in the focus of heterotopic hemopoiesis. At administration of dipiridamol a phenomenon of noneffective megakaryocytopoiesis with the intrabone marrow destruction of megakaryocytes, resulting in local release of thrombocyte growth factor, which has a compensatory character.     

Selection of a Microbial Community in the Course of Formation of Acid Mine Drainage

Microbiology - Changes in microbial community composition during formation of an acid mine drainage were studied on a model of two water reservoirs located in the Ozernoye open-cast mine for...     

Variability of the composition of the microbial community of the deep subsurface thermal aquifer in Western Siberia

The deep subsurface biosphere is one of the least studied ecosystems on Earth, containing communities of extremophilic microorganisms. The present work was aimed at molecular genetic characterization of microbial communities of underground thermal waters in Western Siberia, lying at depths of 2–3 km. Water samples were collected from the 5P oil-exploration well, drilled to a depth of 2.8 km near the village Chazhemto (Tomsk region). The water had a temperature of about 20°C, a neutral pH and a low redox potential (–304 mV). Underground aquifers have a complex structure and may contain both planktonic microorganisms and those immobilized on the surface of rocks in the form of biofilms, which may be washed out and detected in the water flowing out of the well. Community composition was analyzed by amplification and pyrosequencing of the 16S rRNA gene fragments in seven water samples taken at different times during 26 hours. Bacteria, which constituted about half of the community, were represented mainly by uncultured lineages of the phyla Firmicutes, Ignavibacteria, Chloroflexi, Bacteroidetes, and Proteobacteria. Archaea belonged mainly to known methanogens of the genera Methanothermobacter, Methanosaeta, and Methanomassiliicoccus. Analysis of the samples taken at different times revealed large variations in the content of most groups of bacteria, with a decrease in Firmicutes abundance accompanied by an increase in the shares of Ignavibacteria and Chloroflexi. The share of archaea of the genus Methanothermobacter varied slightly during the day, while significant variations were observed for the phylotypes assigned to Methanosaeta and Methanomassiliicoccus. Hydrogenotrophic archaea of the genus Methanothermobacter are probably a permanent component of the microbial community occurring in the planktonic state, while most of the identified groups of bacteria are present in biofilms or spatially localized parts of the underground water reservoir, the material of which accidentally enters the well.     

Effect of metal concentration on the microbial community in acid mine drainage of a polysulfide ore deposit

The composition of microbial communities of acid mine drainage (AMD) in two wells drilled in the terrace of the Sherlovaya Gora open-cast polymetallic ores mine (Eastern Siberia) was studied. While drainage water filling two wells, ShG14-1 and ShG14-8, had similar values of pH (2.6), Eh (447–494 mV), and temperature (6.5°C), the water in the first well contained more metals and sulfate. The water in ShG14-1 and ShG14-8 contained, respectively, 1898 and 434 mg/L of iron, 734 and 49 mg/L of manganese, 81 and 7 mg/L of copper, 3597 and 787 mg/L of zinc, and 15990 and 3632 mg/L of sulfate. Molecular analysis of the microbial communities was performed using pyrosequencing of the 16S rRNA gene fragments. The ShG14-8 microbial community included such bacterial taxa typically found in AMD sites as Gallionella (38.8% of total 16S rRNA gene sequences), Ferrovum (4.4%), Acidiphilium (9.1%), Acidisphaera (8.2%), Acidithiobacillus (7.2%), and Leptospirillum (4.6%). In the ShG14-1 sample with higher content of metals, strict acidophiles Acidithiobacillus (16.0%) and Leptospirillum (25.4%) were more abundant, while Gallionella, Ferrovum, Acidiphilium and Acidisphaera were almost absent. Ferrimicrobium (16.8%) and Sulfobacillus (1.4%) were detected in ShG14-1 but not in ShG14-8. Thus, the increase in concentration of metals in the acid mine drainage water under the same value of total acidity substantially altered the composition of the microbial community, preventing the development of “moderate” alpha- and beta-proteobacterial acidophiles, so that the community was dominated by the bacteria characteristic of the extremely acidic drainage waters.