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V M Andreev

Publications and source records attributed to V M Andreev.

At least 19 recordsLinked to original sources
PubMed2006

[A novel method of transfection of marine bacteria Pseudoalteromonas espejiana with deoxyribonucleic acid of bacteriophage PM2].

DNA of bacteriophage PM2 is a convenient test object for studying DNA-damaging genotoxic agents. The extent of DNA damage can be estimated by the ability of damaged DNA for transfection of host cells, marine bacterium Pseudoalteromonas espejiana (Pae), str. BAL-31. The efficiency of transfection of Pae lines maintained for long periods without freezing was found to be very low upon the use of a widely accepted transfection method developed by van der Schans et al. (1971). Such cultures grown in a medium with 10 mM Ca2+ standard for Pae contained cell aggregates and exopolymer material. Pae was found to be capable of growing in a medium without the calcium supplement in the presence of chelator EGTA (low-calcium medium, LCM). After growth in LCM, cells did not aggregate, cultures lacked the activity of nuclease BAL, and transfection efficiency of cells grown in LCM drastically increased. Based on these results, a novel procedure of transfection with an efficiency of 2 x 10(4)-2 x 10(5) infectious centers per microgram of PM2 DNA was developed.

Corticoviridae↗
PubMed1999

[Spontaneous mutants of Alteromonas espejiana, resistant to kanamycin and bleomycin].

An attempt was made to induce insertions in marine bacterium Alteromonas espejiana Bal-31 (Ae) using the TnphoA transposon. The Ae mutants selected on a kanamycin-containing medium after conjugation of the Ae with the transposon donor, Escherichia coli SM10(pRt291), were resistant not only to kanamycin (Kn), but also to bleomycin (Bm), and were sensitive to tetracycline. Although the mutants were phenotypically similar to insertion mutants, the mutations appeared to be spontaneous. The sensitivity of spontaneous Kmr Ae mutants selected at various Km concentrations to Bm was investigated. The mutants selected at low Km concentrations were resistant to Bm, whereas those selected at high Km concentrations were sensitive to Bm. The possible mechanisms underlying the dual resistance to Bm and aminoglycosides in bacteria are discussed.

Alteromonas↗
PubMed1990

[Loss of adsorptive ability--the reason for inactivation of the RM2 bacteriophage during storage].

The kinetics of bacteriophage PM2 inactivation at storage was compared with the kinetics of bacteriophage adsorption on Alteromonas espejiana BAL-31 host cells. Adsorption ability and infectivity are lost with the same rate at temperatures 4-28 degrees C suggesting the loss of adsorption ability to result in bacteriophage inactivation. At higher temperatures infectivity is lost more rapidly than the ability of adsorption. The single hit kinetics of adsorption ability loss suggests the simple model of independent inactivation of 12 antireceptors located at the tops of icosaedric capsid to be erroneous. At bacteriophage inactivation the major port of protein I, a fragment of antireceptors, is preserved in the capsid composition.

Bacteriophages↗
PubMed1990

[Inactivation of bacteriophage PM2 during storage].

The kinetics of bacteriophage inactivation in the medium that is optimal for its storage has been studied at temperatures from 4 to 55 degrees C. The plot of Arrhenius dependence of the constant of inactivation rate consists of the two linear parts with the energies of activation Ea = 25 kcal/mol for 4-37 degrees C and Ea = 91 kcal/mol for 37-55 degrees C. The DNA of inactivated bacteriophage remained mostly in superspiralized form and completely preserved its biological activity as tested by transfection in spheroplasts. The analysis of inactivation kinetics suggests ageing of virions cultivated at 4 degrees C. The addition of watersoluble antioxidant amoxipin did not change the inactivation kinetics. The addition of antioxidant ionol with twin-80 increased the inactivation that was paralleled by the bacteriophage DNA degradation.

Bacteriophages↗
PubMed1989

[Significance of van Merten's index in the diagnosis of ventilation-perfusion disorders and causes of respiratory insufficiency].

The ventilation-perfusion correlations were studied in 30 normal persons and in 60 patients with chronic heart and pulmonary diseases with the aid of van Marten's index (RCO2). It is shown that capnographic determination of the index is of paramount importance in the diagnosis of ventilation-perfusion disorders and of the causes of respiratory failure since the index rises only in patients with the clinical signs of obstructive ventilatory insufficiency.

Coronary Disease↗