Mirror symmetry breaking in biochemical evolution.

The problem of origination of molecular asymmetry in biochemical evolution is discussed. The theoretical analysis shows that chiral purity of biomolecules has the biological significance for self-reproduction of organisms. The models of spontaneous symmetry-breaking in molecular systems are given. The aspects of various stages of biochemical evolution associated with the development of chiral polarization are analysed.     

Participation of GABA and glycine in the formation of somato-sympathetic reflexes]

Experiments were conducted on cats with intact spinal cord, and after spinalization a study was made of the action of strychnine and picrotoxin (synaptic GABA and glycine antagonists) on the components of somatosynaptic reflexes caused by stimulation of the skin and muscular intercostal afferents. Induced potentials were recorded in the white ramus of the third thoracic segment. The action of strychnine and picrotoxin on the values of different reflex components was not identical; this pointed to a different localization of the inhibitory action of GABA and glycine in the central link of the somatosympathetic reflex arch.     

Effect of thymalin on the thymus and immunologic indices of irradiated animals

The intramuscular injection of thymaline (1 mg/kg/day during 5 days) enhanced the regenerative processes in the thymus and favored the normalization of some immunological indices of irradiated guinea pigs.     

Use of rooms with laminar air flow]

The paper deals with the problem of dependency of the reduction of microbial contamination and of dust pollution of the air mediu min the CAMERA-BOXES with a liminary flux on the aeration degree. It was shown that the degree of aeration in the camera-box constituted from 330 to 1060, with the rate of the air flux at the filter exit of from 0.2 to 0.6 m/sec. Vertical laminar flux provided release of the air from the microbes and dust. The use of the camera-box with a laminar flux for work requiring sterile conditions is recommended.     

High-resolution electrophoresis in a new polyacrylamide-gel block

A new gel block for electrophoretic separation is offered. When viewed frontally, the block has a form of a trapezium. During electrophoresis a gradient of voltage is formed in such a block, as a result of which the mobility of macromolecules to be separated markedly decreases. The combination of the block with polyacrylamide gel gradient makes it possible to raise the resolving power of electrophoresis up to 300-400 dalton. The new gel block can be applied successfully to the performance of fine biochemical assays and molecular-biological studies of proteins, glycoproteins and nucleic acids.     

The action of osmolytes on the destructive effect of ionizing radiation,hyperthermia, microwave radiation,and ultrasound

New data on the influence of osmolytes (NaCl, glycerol) on the destructive effect of ionizing radiation, hyperthermia, microwave radiation and ultrasound were obtained from experiments with bacterial cells. The pattern of manifestation of the osmolyte protective effect is presented. It was found that the protective effect of osmolytes from damaging factors (antagonistic interaction) can be detected only within a certain range of agent “doses.” Inside this range, there is an optimum providing the maximum protection. It was shown that, to provide the highest antagonistic effect with increased intensity of one of the agents, a corresponding change in the intensity of the other agent involved in the interaction is required. It is concluded that, in addition to DNA damage, membrane injury and osmotic homeostasis system may be considered as critical targets in cell destruction after the combined action of various environmental factors.     

Interaction of s4U8 region of tRNA Phe with tRNA-(adenine-1-)-methyltransferase from Thermus thermophilus

Photoaffinity labelling of tRNA (adenine-1-)-methyltransferase with an E. coli tRNA(Phe) derivative bearing 4-azidophenylmercuro group attached to s4U residue as well as direct photocross-linking of the native tRNA(Phe) with the enzyme via s4U residue has been studied. Both techniques labelling gave similar results, leading to covalent attachment of tRNA(Phe) to the enzyme within a specific complex. The data obtained indicate unambigously that s4U residue contacts with tRNA (adenine-1-)-methyltransferase within the corresponding specific complex.