Biomedical subjects

A V Usatov

Publications and source records attributed to A V Usatov.

6 recordsLinked to original sources

PubMed2005

[The effect of oxidative stress on nitrosomethylurea-induced mutagenesis in sunflower Helianthus annuus L].

The effect of hyberbaric oxygenation on mutagenicity of nitrosomethylurea (NMU) was examined. It was shown that in the regimes studied, hyperbaric oxygenation enhances the NMU mutagenic effect both on the nuclear and on the plastid genetic material of sunflower, but do not increase intensity of free-radical reactions and do not induce plastid mutations and chromosome aberrations per se. At high concentrations inducing chromosome aberrations (0.03%), NMU was shown to enhance the level of free-radical processes. Possible mechanisms of the increase of NMU-induced mutagenesis by hyperbaric oxygenation are discussed.

Chromosome Aberrations↗

PubMed2004

[Spontaneous and induced nitrosomethylurea reversion of plastomic chlorophyll mutants of the sunflower Helianthus annuus L].

Spontaneous and induced revertants obtained from plastome chlorophyll mutants of sunflower were subjected to genetic analysis. The mechanism of reversion (nuclear suppression, plastid suppression, true reversion, or mitochondrial suppression) of the plastid mutation was shown to affect the degree of restoration of morphological and physiological traits of sunflower plants.

Chlorophyll↗

PubMed2004

[The ultrastructure of Brassica junceae chloroplast as a criterion of salt resistance].

Two salt resistant forms of the mustard Brassica junceae were obtained. These forms demonstrated no chlorophyll defects. SR2 and SR3 salt resistant forms have constant parameters of productivity in condition of NaCl salting, in comparison with the initial plants of sort Donskaya-5. Results of a comparative ultrastructural analysis of plastids show that the salt influences the plastid ultrastructure of SR2 and SR3 lines of mustard in a lesser degree in comparison with the sort plants. The plastids of SR2 and SR3 salt resistant lines of mustard are functionally quite active under stress conditions.

Chloroplasts↗

PubMed2001

[Heat shock modification of nitrosomethylurea action on sunflower seedlings].

Separate and combined action of nitrosomethylurea (NMU) and heat shock (HS) on germination of seeds of the inbred line 3629 and derived nuclear and plastome mutant lines, n-chlorina-1 and en-chlorina-5, respectively, were studied. NMU at a concentration of 0.015%, as well as HS (40 degrees C), had no effect on the spontaneous level of chromosome aberrations in root meristem of sunflower seedlings. However, at a concentration of 0.03%, the mutagen considerably increased the frequency of chromosome rearrangements. Pretreatment with heat for 30 min enhanced the cytogenetic effect of NMU (0.03%) on line 3629 seedlings. In the nuclear mutant, the reaction of root meristematic cells did not depend on the additional heat treatment. The combined action of HS and NMU at early germination stages had no effect on the survival of line 3629 plants and plastome mutant en-chlorina-5; the survival of n-chlorina-1 plants decreased. The highest frequency of M1 plants with chlorophyllic abnormalities (green revertants, lethals, and variegated forms) was observed in n-chlorina-1 line.

Heat-Shock Response↗

PubMed2001

[Mutagenic effect of nitrosomethylurea, modified by heat shock at early stages of sunflower seedling development].

A comparative study of chlorophyll mutations induced in sunflower seedlings of the initial line 3629 and its nuclear and plastom mutant derivatives by nitrosomethylurea (NMU) (0.015%), heat shock (HS, 40 degrees C), and their combination was performed. The spectrum and frequency of chlorophyll mutations depended on the treatment conditions and on the genotype of the lines tested. Nuclear mutant displayed highest sensitivity to NMU, HS, and their combination. The line 3629 plants displayed highest tolerance to NMU and HS. However, plastom mutants were more tolerant to the combination of the mutagens compared to the plants of the initial line.

Adaptation, Physiological↗

PubMed1994

Molecular neural network devices based on non-linear dynamic media.

The importance of non-linear dynamic mechanisms for implementing neural network devices at a molecular level is discussed. Information processing devices based on these mechanisms proved to be capable of performing some primitive operations important for image processing.

Algorithms↗