Site-directed mutagenesis in the uracil-repair system. Preparation of mutated forms of human alpha 2 interferon

The mutant forms of human IFN-alpha 2 gene are obtained by oligonucleotide-directed mutagenesis with the use of uracil-repair system. To intensify the process the procedure of the uracil-containing DNA template preparation is modified. It was determined that when mutagenesis is performed in the uracil-repair system the yield of the process depends on the mutant DNA-strand in vitro synthesis efficiency. It is shown that the stability of the 5'-end primer-template complex and the level of the endogenic primers elongation are the basis factors, that determine induction mutations.     

Vertical distribution and cellular heat resistance of bottom animals from the Possyet Bay (Japan Sea)

Summary 1. Investigations on 15 mass species of bottom animals (Bivalvia, Gastropoda, Asteroidea, Ascidia), performed by means of aqualungs in semi-enclosed bays of the Possyet Bay (Peter the Great Bay of the Japan Sea), have revealed a clear zonality in their vertical distribution. This finding is in contrast to the situation found near islands and capes of Peter the Great Bay, where species distributions are weakly connected with depth, but to a considerable degree determined by the nature of substrate, degree of tides and presence of predators.2. These differences may be explained by differences in summer temperature conditions, considerable decrease of the temperature gradient with increase of depth in semi-enclosed bays, insignificant surface temperature differences and, in depths of about 20–30 m, by intensive water mixing near islands and capes.3. Comparison of the vertical distribution of species from the Possyet Bay with their cellular heat resistance (species-specific feature, used for characterizing genetic heat adaptation) reveals conformity between these indices.4. These results and literature data suggest that the differences in vertical distribution of the bottom invertebrates living in coastal waters are the result of the species-specific adaptation of their cells to environmental temperature; differences in protein structure of different animals are considered to provide the basis of this phenomenon.

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Vertikalverbreitung und zelluläre Hitzeresistenz von Bodentieren aus der Possjet-Bucht (Japanisches Meer)

Kurzfassung Die vertikale Zonierung verschiedener benthonischer Tiere, die in halbgeschlossenen Buchten des Japanischen Meeres untersucht wurden, weicht von den im gleichen Gebiet an Inseln und Steilabhängen festgestellten Tiefenverbreitungen ab. Diese Unterschiede können von der Art des Substrats, der Gezeitenwirkung, den Strömungsverhältnissen und insbesondere von den Temperaturbedingungen abhängen. Ein experimenteller Vergleich der zellulären Hitzeresistenz von Cilienepithelien verschiedener Muschel- und Ascidien-Arten und deren Vertikalverbreitung konnte vor allem den Einfluß der Temperatur deutlich machen. Es wird die Schlußfolgerung gezogen, daß artspezifische Anpassungen an die Umgebungstemperatur, die offensichtlich auf Unterschieden in der Proteinstruktur beruhen, die Vertikalverbreitung von Bodentieren entscheidend mitbestimmen.

     

Alkaline sucrose as a solvent for delivery of water-insoluble drugs

Alkaline sucrose solution was demonstrated to be a good solvent for the solubilization of water-insoluble drugs. At high concentration and alkaline pH, sucrose solubilizes water-insoluble molecules through intramolecular conformations. Tetracyline and chloramphenicol, when dissolved in alkaline sucrose solution, retained their bactericidal activity. Gel permeation-chromatography analysis and atomic-force-microscopy studies confirmed the formation of sucrose-antibiotics complex.     

Evaluation of the professional qualities of operators working with computer displays

The influence of spatio-temporal factors (spatial heterogeneity of distribution of the numbers sought for in the matrix of data, processes of learning and development of fatigue, periodic attention oscillations) of the character of solving the task of searching the numbers in a matrix of 176 three-figure numbers (16 lines, 11 columns) was studied in 39 operators. The possibility was shown to use the characteristics obtained for evaluation of professionally important abilities of an operator working at the display.