Construction of a gene coding for the precursor of human tumor necrosis factor]

The cDNA sequence for human tumor necrosis factor (hTNF) was reconstructed in vitro from genomic sequence. Using the oligonucleotide directed mutagenesis, a site for restriction endonuclease ClaI was introduced into the end of the first exon. The nucleotide sequence representing the second and third exons flanked with restriction sites ClaI and XhoI was obtained by means of chemical enzymatic synthesis. Assembly of the total gene coding for precursor of hTNF was accomplished in pTNF33 plasmid containing semisynthetic gene for mature hTNF with appropriate restriction sites.     

Bacillus subtilis soil isolates: plasmid replicon analysis and construction of a new theta-replicating vector

We have searched for plasmids in a collection of 55 Bacillus subtilis strains isolated from various natural sources of the territory of Belarus. Twenty percent of the strains contained one or two plasmids of either 6-8 or approximately 90 kb. Small plasmids were shown to carry a rolling circle replicon of the pC194 type. Four out of the eight large plasmids contained a related theta replicon that has no homolog in databases as shown by sequence determination. A B. subtilis/Escherichia coli shuttle vector based on this replicon was constructed. It has a low copy number (6 units per chromosome) and is stably inherited in B. subtilis. It might thus be a useful tool for DNA cloning. These data extend previous observations, indicating that most of the small plasmids of B. subtilis replicate as rolling circles and belong to the pC194 family. On the contrary, large plasmids appear to form a large pool of theta-replicating determinants, since three different replicons have already been isolated from them.     

Frequency of mutagen-induced sister chromatid exchanges in the course of 3 cell cycles

The induction of SCE by fotrine (0.125 and 0.250 microgram/ml) and thiophosphamide (5 micrograms/ml) during the first three cell cycles was studied in the Chinese hamster cells. No increase in the SCE number was observed after treatment with thiophosphamide and fotrine at the G2 stage (the first stage from the moment of fixation) as compared with the control variants. The maximal sensitivity of the cells to the SCE induction by the mutagens is marked at the G1 stage of the first cell cycle before the moment of fixation. The level of SCE remains approximately the same in the second cell cycle before the moment of fixation (20-32 h) and decreased down to the control level at the G1 stage of the third cell cycle (48-52 h).     

Population identification of Helicobacter pilory isolates from Russia

Using multilocus sequence typing (MLST), 22 Helicobacter pylori isolates from Russia have been characterized. All of the Russian strains were assigned to a single population, hpEurope.     

A study of the effect of irradiation hardness on the properties of the fluoropolymeric matrix modified by polyanionic biologically active substances

The properties of a synthetic substrate responsible for the behavior of substrate-dependent cells in the culture were studied. The effect of the composition of a system water-soluble biopolymer (sodium alginate or methyl cellulose)-synthetic latex SKF-26 and the effect of various types of radiations on its biophysical properties were studied. The results obtained indicate that the addition of water-soluble biopolymeric additives to synthetic polymeric films improves the adhesion of cells to the substrate, the adhesion being closely related to the concentration of additives. It was found that the modification methods that determine changes in the charge of the substrate affect the capacity of different cell types for adhesion and proliferation. It was also found that the hardness of irradiation does not affect the vapor permeability and the extent of film swelling.     

Effect of duration of the intervals between immunization with DPT vaccine on the serological indices in children

The influence of the interval between injections of adsorbed DPT vaccine on the effectiveness of immunization has been studied. The intensity of antibody formation to the pertussis component has been found to decrease 2.7-3.7 times if the interval between the injections constituting the course of primary immunization is prolonged for more than 6 months. The interval between the course of primary immunization and the first booster injection, which lasts 1.5-2 years in accordance with the currently accepted immunization schedule, is unreasonably long. Immunological characteristics in respect to pertussis have been found to decrease 8-45 times as early as 16 months after the first booster injection. Most of the vaccines catching pertussis at that time had the moderately severe form of this infection.     

Reorganization of Composition of Striatal Neurons Correlating with Behavior in the Monkey Macaca nemestrina

The available experimental data do not provide a sufficiently complete picture of the neuronal activity connected with some action of the animal, as they have been obtained under different experimental protocols and as a result of study of different cells. The present work was aimed at studying activity of the same neuron group at different moments of animal's behavior. A monkey (Macaca nemestrina) was taught to perform a behavioral program consisting of several functional heterogeneous actions. The impulsive activity of striatal neurons was recorded in the central region of putamen with coordinates A 16.5, L7, and H 8–10 [18]. The activity of each neuron was recorded during 13 consecutive stages of the same behavioral task. As a whole, in 59 putamen neurons, 767 fragments of neuronal activity were studied. It was shown that the same neurons could be involved at different behavioral stages when the animal performed different actions. At individual stages, the number of neurons common with other behavioral stages reached 70–80% of all reactive cells at the stage. The number of the neurons common within the rest of 12 stages was determined for every program stage. The number of such common neurons established in the experiment was in 142 out of 156 cases higher than their number that could be expected on the basis of statistical relations. The data obtained indicate that the reorganization in composition of behavior-reactive cells at every behavioral stage occurs mainly by using the same neurons but not only the neurons that are specialized for the given action. The polymodality of individual striatal neurons is unlikely to be connected with that they have several functions, but results from that the same neuron can be a constituent of neuronal mosaics of different configurations corresponding to different behavioral moments.