[Effect of space flight and head-down position on motoneuron- glia-capillary system of the rat bone marrow]. / Vliianie kosmicheskogo polëta i vyveshivaniia v antiortostaticheskom polozhenii na sistemu "Motoneiron-gliia-kapilliar" spinnogo mozga krys.

In the anterior horns of the rats exposed to a 14 day space mission and 8-11 hrs of earth gravity environments postflight there occurred morphologic changes pointing to the motoneuron hypofunction which was expressed to a greater extent in motoneurons at C3-C4 level than at L4-L5 level. As the time of the rat stay under Earth gravity conditions following 14-day space mission is increased up to 48-51 hrs the structural changes in the motoneuron-glia capillary system at the L4-L5 level is indicative of an activation of spinal cord motoneurons. The 14 day head-down suspension (HDS) of the rats results in the morphologic changes in anterior horns which are an indication of hyperfunction of motoneurons in cervical enlargement and hypofunction of motoneurons in lumbar enlargement of the spinal cord. An increase of HDS time up to 32 days intensifies the morphologic changes in lumbar enlargement motoneurons. A lesser extent of morphologic changes manifestation in the motoneuron-glia-capillary system at L4-L5 level in the rats following a 14-day HDS as compared to the rats exposed to 14-day space mission is indicative of more slower development of motoneuron hypofunction under Earth gravity conditions as opposed to space environments.

[Structuro-functional organization of the blood-brain barrier]. / Strukturno-funktsional'naia organizatsiia gematoéntsefalicheskogo bar'era.

The analysis of the authors and published data allowed to conclude that the blood-brain barrier was a complex structural-functional system. Its basic components are endothelial cells, basal membrane, pericytes, tissue basophils, and astrocytes. The role of these structural elements in the permeability of blood-brain barrier has been studied. Organ-specific peculiarities of the brain tissue basophils have been established in rats, cats, and dogs. The astrocyte-capillary complexes were found to be very reactive, and at the same time, very plastic CNS structures.

[Morphological analysis of the reaction of the animal brain to short-term hyperoxia]. / Morfologicheskii analiz reaktsii golovnogo mozga zhivotnykh na kratkovremennuiu giperoksiiu.

Reactions of various structures of the central nervous system of animals to short-term hyperoxia were investigated, using morphological methods available. Reactive, destructive and compensatory-adaptive changes in the structures taken under study were identified. These changes were nonspecific and similar in sign in rats and dogs. In most cases they were reversible but their polymorphism was different in phylogenetically dissimilar structures.

[Neurocyte reaction of the kinesthetic analyzer of rats to the action of vibration]. / Reaktsiia neirotsitov kinestezicheskogo analizatora krys na deistvie vibratsii.

By neurohistological, morphometric and electron-microscopic methods the effect of vibration of 80 Hz applied at an acceleration of 8 m/sec2 on the nerve cell and conduction components of the kinesthetic analyzer was investigated. After a single exposure to vibration nerve cells of the sensorimotor cortex showed some changes. Exposure to vibration for as long as a week caused reactive changes in every structure of the kinesthetic analyzer investigated. After 1-month exposure the changes were more disseminated and became destructive, after 2-month exposure the process developed at a slower rate, and after 3-month exposure it remained at the same level. However, after 3-month exposure the morphological equivalent of compensatory-adaptive reactions was seen.

[Dynamics of morphologic changes in joint innervation during hypokinesia--a space flight model factor]. / Dinamika morfologicheskikh izmenenii nervnogo apparata sustavov pri gipokinezii--model'nom faktore kosmicheskogo poleta.

Using statistical treatment, a neuromorphological examination of the joint capsule of rats exposed to hypokinesia for 7, 15, 20, 30, 40, and 60 days was carried out. The exposure to 7 days caused an increase in the number of reactively changed nerve fibers and receptors. The exposure to 15 days resulted in a significant increase of the number of nerve fibers with destructive changes that involved mostly large-caliber fibers. However, 20- and, especially, 30-day hypokinesia was followed by a significant reduction of destructive changes. After 40- and 60-day exposure they again became very distinct. This suggested a wave-like pattern of structural changes. At every stage of experimental hypokinesia all the compartments of the joint nervous apparatus showed adaptive-compensatory reactions.

[Biological effects of the action of a high-tension DC electrical field]. / Nekotorye biologicheskie éffekty deistviia postoiannogo élektricheskogo polia vysokoi napriazhennosti.

The experiments were carried out on 345 white mice using hematological and pathomorphological procedures. The constant electric field (CEF) was generated in a special laboratory device. The exposure to CEF of 50 and 100 kV/m for 20 s caused hematological and morphological changes typical of the anxiety stage of the adaptation syndrome. The exposure also produced morphological changes of reactive and destructive type in skeletal muscles and different segments of kinesthetic receptors. The level of the above changes appears to be directly related to the CEF strength.

[Phenotypic expression of plasmid pPL7065 in Bacillus pumilus in free and integrated states]. / Izuchenie fenotipicheskogo vyrazheniia plazmidy pPL7065 Bacillus pumilus v svobodnom i integrirovannom sostoianii.

There are about 20 copies of pPL7065 plasmid in cells of Bacillus pumilus ATCC7065 with molecular weight of 4.7 X 10(6) daltons. A spontaneous purine dependent mutant LK1 was isolated which contained no autonomous plasmid. However, the presence of the plasmid in LK1 cells was proved by DNA - DNA hybridization. To accomplish this, hybrid plasmid p1G1 was constructed by cloning pPL7065 on a vector pBR322 and multiplying it in Escherichia coli C600. The plasmid then was hybridized with chromosomal DNA of Bac. pumilus LK1. A pur+ revertant has been obtained from LK1 containing autonomous plasmid pPL7065, similar to the parental strain ATCC7065. These results are indicative of pPL7065 integrated into the chromosome of LK1. Bacteria having the autonomous plasmid are oligosporogeneous and produce specific antibiotics. Integration of the plasmid into bacteria causes pur phenotype, normal sporulation and a change in antibiotic synthesis and resistance. LK3 strain which lost pPL7065, sporulates normally and produces the antibiotic that inhibits growth of Bac. pumilus ATCC7065.

[Effect of low doses of chloramphenicol on ribosomal precursor formation in E. coli cells]. / Vliianie nizkikh doz khloramfenikola na obrazovanie predshestvennikov ribosom v klekakh E. coli.

RNA synthesized in the cells of E. coli CP 78 (rel+) in the presence of chloramphenicol low concentrations (5 microgram/ml) was found in 30S and 50S subunits and monosomes. A significant part of it was alotted to ribonucleoproteid or chloramphenicol particles. The protein content of ribonucleoproteid amounted to 22-25% and the content of RNA in it was equal to 78-75%.

Effect of beta-indoleacetic acid on RNA and protein synthesis in Escherichia coli.

The effect of different concentrations of beta-indoleacetic acid (IAA) on RNA and protein synthesis and the stability of associations of E. coli ribosomes at 3 mM Mg2+ was investigated. IAA in a concentration of 100 microgram/ml had a slight stimulatory effect on the incorporation of [14C]leucine into proteins and stimulated the incorporation of [14C]uracil into the RNA of intact cells more noticeably. In the presence of 2500 microgram/ml of the auxin RNA synthesis was inhibited by 65% and protein synthesis by 40-50% as compared to the control. In a cell-free system containing poly(U) IAA in concentrations of 10-100 microgram/ml increased polyphenylalanine synthesis by an average of 30%, while at high concentrations IAA noticeably inhibited its synthesis. It was found that the proportion of stable ribosomes in lysates obtained from cells incubated with IAA in concentrations of 250 and 1000 microgram/ml decreased to 18 and 3%. It is suggested that the inhibition of protein synthesis in E. coli by IAA is due to inhibition of the initiation of translation.

[Translation of poly U by ribosomes from rel+ and rel- E. coli strains]. / Transliatsiia poli-U ribosomami iz kletok rel+ i rel- -shtammov E. coli.

A translation of polyU in a cell-free system from CP78 (relA+) and CP79 (relA-) E. coli strains is investigated. The strains studied no not differ in misreading at Mg2+ concentration of 20 mM and concentrations of 16 mM (optimal for phenylalanine incorporation) and 18-22 mM (optimal for leucine incorporation) respectively. It is found that leucine incorporation increases similarly in both strains under conditions simulating an amino acid deficience (in phenylalanine-free incubation medium): the ratio leucine(-phenylalanine)/leucine (+phenylalanine) is 3.5-4 at a concentration of enzymatic fraction protein being 15-30 mkg per example, and it is 2 st a concentration of enzymatic fraction of 60-180 mkg of protein. It is suggested that differences in activities of a number of enzymes under amino acid starvation in Rel+ and Rel- cells are not due to differences in the precision of mRNA translation, but depend on the activity of respective genes.

[Mathematical analysis of myelin structure of nerves of the brachial plexus in antenatal and early postnatal ontogenesis of man]. / Matematicheskii analiz mieloarkhitektoniki nervov plechevogo spleteniia v antenatal'nom i rannem postnatal'nom ontogeneze cheloveka

A gradual increase of the information entropy indices and a decrease of the excess percentage is observed in the course of antenatal and early postnatal ontogenesis of man. The indices of the information entropy reach their maximum and the excess percentage reaches its minimum in children younger than 3 years. At that time the myelinated fibres have the most various diameters. In the antenatal development of man the prevalence of fine (1--4 mkm) myelinated fibres makes the structure of the humeral plexus nerves more definite while in the postnatal ontogenesis their structure is less definite since the myelinated fibres of different diameter are met with almost the same probability.

[Effect of streptomycin on RNA synthesis in E. coli cells]. / Vliianie streptomitsine na sintez RNK v kletkakh E. coli

Under streptomicin administration (10-200 mug/ml), initiation of translation is blocked at any steps before the formation of tightly bound subunits. Incomplete supression of protein synthesis with streptomycin stimulate rRNA synthesis in rel+ CP78 E. coli cells. Thus, partial uncoupling of translocation and transcription promotes compensatory synthesis of rRNA synthesis directed by rel-gene, but on addition to pre-starved cells, antibiotic can not stimulate rRNA formation. It is shown, that in contrast with many other ribosomal antibiotics streptomycin do not penetrate into the cell during aminoacid starvation.