Effect of stress factors on carboxypeptidase H activity in areas of the rat brain]

It is established that carboxypeptidase H activity increases as affected by various stress factors in the rat brain departments. The increase of the enzyme activity because of the emotional-pain stress is of continuous character. Possible role of carboxypeptidase H in the development of the stress response is discussed.     

Thermotropic behavior of liposomes from egg yolk lecithin, hydrogenized egg yolk lecithin and their mixtures

The thermotropic properties of multilamellar liposomes from egg yolk lecithin, hydrogenized egg yolk lecithin and several mixtures of these two lipids were studied with the application of excimer--forming optical probe pyrene and microcalorimetry. It was discovered that when the proportion of the egg yolk lecithin in the lipid mixture was raised the temperature of the main phase transition reduced. For all this, independent of the lipid mixture composition when the temperature was raised, apparently, polarity of pyrene microenvironment in the liposomes bilayers decreased. On the basis of the analysis of solidus and liquidus curves obtained from calorimetric studies of the lipid mixtures and bend points of Arrhenius anamorphose obtained during the pyrene excimer formation measurements some conclusions were made about the role of unmodified and hydrogenized egg yolk lecithin cluster formation in the determination of thermotropic properties of the liposomes from the above two lipids mixtures. High temperature phase transition discovered for the egg yolk lecithin while measuring the pyrene excimer formation is proposed to be closely connected with temperature-dependent changes in the organization of phospholipid heads on the interphase bilayer/H2O solution.     

Cloning of the DNA fragment of a transgenic mouse containing an integrated recombinant plasmid

The "plasmid rescue" method has been used to isolate the recombinant plasmid pMA3 fragment and flanking sequences from the transgenic mouse genome containing the fragment in integrated form. The "rescued" plasmid, pMAR1, lacks all virus sequences and retains only those regions of pBR322 that are responsible for the plasmid replication and Escherichia coli ampicillin resistance. The plasmid pMA3 deletion has occurred at its integration into the mouse genome after microinjection into the zygote. The integrated fragment of the plasmid is adjacent to the genome repeated sequence that is highly conservative in evolution.     

Increase in the sensitivity and a simplification of the method for the separate determination of antibiotic activities in combined preparations (oletetrin) by using media with a varying pH value

An agar-diffusion method for determination of oleandomycin and tetracycline low levels in solutions of the drug combination was developed. The medhod may be used for investigation of oletetrin absorption and distribution in humans and animals. It provides high accuracy in separate determination of oleandomycin and tetracycline activity in solutions of the drugs at a ratio of 1 : 2. The same test-culture, Bac. subtilis, variant L2 is used for the assay of tetracycline and oleandomycin activity. The only differences are in the values of pH and the buffer solution and the standards.     

Comparison of structural and functional organization of adrenocorticotropic hormone and wasp kinin]

A comparative study of structural and functional organization of the polypeptides -- ACTH and wasp kinin was made. The effects of fragments Lys 17, 18-ACTH11(-18)-NH2--(I) and WK4(-12)--(II), possessing "common" fragments and a cluster of basic amino-acids, on the lipolytic and steroidogenic effects of ACTH and myotropic effects of bradykinin were studied. Both fragments I and II potentiate ACTH-induced lipolysis and steroidogenesis in isolated rat fat and adrenal cells but suppress the myotropic effect of bradykinin on guinea pig ileum. The similarity of biological effects of ACTH and WK fragments support our supposition on the similarity in structurally functional organization of these peptides.     

DIROM: an experimental design interactive system for directed mutagenesis and nucleic acids engineering

A computer system DIROM for oligonucleotide-directed mutagenesisand artificial gene design has been designed for better experimentalplanning and control. DIROM permits searching for optimal oligonucleotideswith respect to certain important parameters, namely sufficientenergy of oligonucleotide-target hybridization, the secondarystructure of oligonuc-tide and target DNA, the presence of alternatebinding sites in the target DNA and terminal G/C pairs. It canalso be used to plan polymerase chain reaction experiments,for optimal primer selection, in sequencing, etc. DIROM enablesone to search for both existing and potential restriction sites,to perform vector + target sequence construction. The systemconsists of a set of original algorithms that formalize theempirical knowledge of oligonucleotide action as primers.     

Effect of Lincocin Treatment on the Greening Process in Bean (Phaseolus vulgaris) Leaves

The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –¹⁴CO₂ fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes.