Modification of silicon nanoparticle surface with gold or silver attenuates its biocompatibility in vitro

The effects of crystalline silicon (Si) nanoparticles covered with gold and silver on the viability and state of cellular organelles of cultured human peripheral blood lymphocytes were investigated. After interaction with Si nanoparticles covered with gold (Si/Au) or with silver (Si/Ag), the reactive oxygen species in cells increased, but their viability was not decreased. The Si/Au nanoparticles decreased functional activity of lysosomes and mitochondria, while Si/Ag decreased the functional activity only of mitochondria. It is concluded that modification of a surface with gold or silver results in a reduction of biocompatibility of crystalline silicon nanoparticles.     

Effects of hypoxia on phosphoinositide turnover and adenylate cyclase system in cultured endothelial cells]

By studying the effects of oxygen deficiency upon signal-transducing system it has been shown that in long hypobaric hypoxia activates PI-turnover in cultured human endothelial cells. The sensitivity of cells to histamine was decreased as well as the adenylate cyclase activity in membranes of this cells. The amount of beta-adrenoreceptors was not influenced significantly. Incubation of endothelial cells with histamine (10(-5) M) and phorbol ester (10(-9) M) = activator of protein kinase C within 1-2 h resulted in desensitization of cellular responses which can be seen not only as a disappearance of histamine-induced activation of PI-turnover but also as a decrease of beta-adrenoreceptor amount and adenylate cyclase activity. It seems that hypoxia may change the action of Ca-mobilizing hormones on PI-turnover and suppress adenylate cyclase in human endothelial cells. However the effects of hypoxia on signal-transducing systems in this cells are developed slower than those of Ca-mobilizing hormones.     

The Effects of Radiation and Hindlimb Unloading on Rat Bone Marrow Progenitor Cells

Bone marrow cells of mesenchymal origin play an important role in adaptation of physiological systems to space flight. Hematopoiesis, immunity, and homeostasis of bone tissue depend on their functional activity. An investigation that was carried out in the framework of the Bion and Bion-M programs showed a decrease of the number of rat bone marrow hematopoietic progenitors and the inhibition of lympho- and erythropoiesis when the granulocyte-macrophage linage was activated. A negative influence on nonhematopoietic bone marrow cells was also revealed. The pathogenetic influence of radiation and microgravity on the bone marrow progenitor cells has remained unclear so far. The goal of this research was to study the effect of a 30-day unloading and 6 days of γ-irradiation on rat bone marrow progenitor cells. The study was conducted on male rats of four groups: vivarium control (VC), hindlimb unloading (HU), irradiation (IR), and combined action (HU + IR). The following parameters have been examined: the number of bone marrow mononuclear cells, proliferative activity of marrow mononuclear cells, immunophenotype, number of hematopoietic CFU and CFU-f, and differentiation potency of hematopoietic and stromal bone marrow precursors. It was found that the cellularity and proliferation activity of rat bone marrow cells did not change under simulation of space flight. The number of CFU-f was decreased. Irradiation was accompanied by an increase in the hematopoietic cell share among total bone marrow mononuclear cells, while their activity was attenuated. The osteopotential of the stromal precursors was unchanged. Adipogenic differentiation was stimulated with irradiation. The functional activity of bone marrow progenitor cells was restored after 2 weeks of recovery. Thus, 30-day simulation of space flight factors negatively affected the morphofunctional properties of rat bone marrow progenitor cells. These effects were reversible upon 2 weeks of recovery.     

First International Workshop on Porcine Chromosome 6

Recent advances in the use of microsatellite markers and the development of comparative gene mapping techniques have made the construction of high resolution genetic maps of livestock species possible. Framework and comprehensive genetic linkage maps of porcine chromosome 6 have resulted from the first international effort to integrate genetic maps from multiple laboratories. Eleven highly polymorphic genetic markers were exchanged and mapped by four independent laboratories on a total of 583 animals derived from four reference populations. The chromosome 6 framework map consists of 10 markers ordered with high local support. The average marker interval of the framework map is 15.1 cM (sex averaged). The framework map is 135, 175 and 109 cM in length (for sex averaged, female and male maps, respectively). The comprehensive map includes a total of 48 type I and type II markers with a sex averaged interval of 3.5 cM and is 166, 196 and 126 cM (for sex averaged, female and male maps, respectively). Additional markers within framework map marker intervals can thus be selected from the comprehensive map for further analysis of quantitive trait loci (QTL) located on chromosome 6. The resulting maps of swine chromosome 6 provide a valuable tool for analysing and locating QTL.     

Specific Features of Metabolism in Humans Performing a Physical Exercise Test after 7-Day Dry Immersion

Healthy male volunteers (n = 5) aged 27–42 years participated in experimental studies (7-day immersion) designed to simulate the effects of microgravity. To study the metabolic changes caused by decreased weight bearing on the musculoskeletal system and a change in the position of the body relative to the gravity vector, a 15-min load test before and after immersion was used. A wide set of biochemical parameters characterizing the state of the energy metabolism, substrate levees, and enzyme activities, as well as the blood level of hormones, was measured in the blood plasma. Multifactor analysis was used in processing the experimental data. After immersion, a significant decrease in the blood plasma activity of isocitrate dehydrogenase, creatine phosphokinase, and lactate dehydrogenase was noted, whereas the growth hormone and insulin levels exceeded the baseline values. The physical exercise test increased the differences in the metabolic status before and after 7 days of immersion. The factor analysis allowed us to reveal the most significant biochemical variables for identifying a new metabolic state of the physiological systems after exposure to short-term simulated microgravity. Changes in the creatine phosphokinase activity and the human blood plasma levels of cortisol, triglycerides, insulin, and inorganic phosphate made the most significant contributions to these differences, and the direction of biochemical shifts in response to exercise was different before and after immersion. The results obtained are indicate that energy and substrate metabolism changes in response to a decrease in weight bearing and an altered body position relative to the gravity vector and that these changes are especially pronounced when an exercise test is used.     

Proinflammatory interleukins' production by adipose tissue‐derived mesenchymal stromal cells: the impact of cell culture conditions and cell‐to‐cell interaction

The impact of culture conditions and interaction with activated peripheral blood mononuclear cells on the interleukin (IL) gene expression profile and proinflammatory IL‐6 and IL‐8 production by adipose‐derived stromal cells (ASCs) was investigated. A microarray analysis revealed a wide range of IL genes either under standard (20%) or hypoxic (5%) O₂ concentrations, some highly up‐regulated at hypoxia. IL‐6 and IL‐8 production was inversely dependent on cell culture density. In early (first–third) passages, IL‐6 and IL‐8 concentration was higher at 20% O₂ and in late (8th‐12th) passages under 5% O₂. Interaction between ASCs and mononuclear cells in indirect setting was accompanied with a significant decrease of IL‐6 and did not result in the elevation of IL‐8 concentration. Thereby, the production of proinflammatory interleukins (IL‐6 and IL‐8) may be affected by the ASC intrinsic features (density in culture, and duration of expansion), as well as by microenvironmental factors, such as hypoxia and the presence of blood‐borne cells. These data are important for elucidating ASC paracrine activity regulation in vitro. They would also be on demand for optimisation of the cell therapy protocols, based on the application of ASC biologically active substances. Copyright © 2015 John Wiley & Sons, Ltd. SIGNIFICANCE PARAGRAPH Ex vivo expansion is widely used for increasing the number of adipose‐derived stromal cells (ASCs) and improving of their quality. The present study was designed to elucidate the particular factors influencing the interleukin production in ASCs. The presented data specified the parameters (i.e. cell density, duration of cultivation, hypoxia, etc.) that should be taken in mind when ASCs are intended to be used in protocols implying their paracrine activity. These data would be of considerable interest for researchers and clinicians working in the biomedical science.