Dependence of the E. coli promoter strength and physical parameters upon the nucleotide sequence

The energy of interaction between complementary nucleotides in promoter sequences of E. coli was calculated and visualized. The graphic method for presentation of energy properties of promoter sequences was elaborated on. Data obtained indicated that energy distribution through the length of promoter sequence results in picture with minima at −35, −8 and +7 regions corresponding to areas with elevated AT (adenine-thymine) content. The most important difference from the random sequences area is related to −8. Four promoter groups and their energy properties were revealed. The promoters with minimal and maximal energy of interaction between complementary nucleotides have low strengths, the strongest promoters correspond to promoter clusters characterized by intermediate energy values

Effect of the low energy electromagnetic radiation of cell phone frequency (1.8 GHz, 2.4 GHz) on the chromatin state in cells of human buccal epithelium

The effect of low energy electromagnetic radiation with frequencies 1.8 GHz and 2.4 GHz on the heterochromatin granules quantity (HGQ) in the nuclei of human buccal epithelium cells was studied. Exfoliated cells were exposed to microwave radiation (frequency 1.8 GHz, surface power density 2.5 μW/cm2; and also frequency 2.4 GHZ, surface power density 2.3 μW/cm2). After exposure to microwaves during 1, 2, and 3 h, immediately or after delay of 1 or 2 h cells were stained with orcein (2% solution in 45% acetic acid). Cell exposure to microwaves induced condensation of chromatin. The biological and medical meanings of the data obtained are discussed

Calculation of experimental apparatus for biological object irradiation by impulse electromagnetic field

The problem of homogeneous irradiation of biological solutions by impulse electromagnetic field is investigated. The optimization of construction and sizes of the apparatus for the irradiation is carried out by direct numerical calculation in time domain. Uniformity of heat distribution is studied

The process of recovery of cell membrane damage produced by the lowlevel microwave radiation

The process of cell membrane recovery after the influence of microwave radiation (f = 36.64 GHz, E = 10, 100, 400 μW/cm2, irradiation time 10 s) on human buccal epithelium cells was investigated. The stainability of cells with indigo carmine (5 mM) or trypan blue (0.5%) after 5 min of staining was investigated. It was shown irradiation to be induced decrease of percentage of unstained cells. Recovery of cell membrane permeability after microwave irradiation was shown. Cell recovery after microwave irradiation of low intensity (10 μW/cm2) was shown after 1 h. Microwave irradiation of higher intensity (100, 400 μW/cm2) induced more strongly effects of cell membrane permeability. Cell recovery after microwave irradiation of higher intensity was shown after 3 h. For the first time recovery of cell membrane after microwave irradiation of low intensity was shown

Simulation of microwave exposure of human cells by electromagnetic field of EMF band

To implement a novel method of investigation of electromagnetic field action on state of cell nucleus the simulation of irradiation of the cells of human buccal epithelium by electromagnetic field of EMF band is carried out. The cells were exposed to radiation of frequency f = 36.64 GHz, with power densities W = 10–1, 1 and 4 W/m2during 10 seconds. To answer on the question of existence of nonthermal biological effect of electromagnetic field onto living cells the specific absorption rate (SAR) of a solution that contained cells is calculated. The numerical simulation based on FDTD method permitted to take into account different parts of experimental setup to obtain real distribution of electromagnetic field inside irradiated solution

Influence of the microwave radiation of different polarization state on transinactivation effect and viability of Drosophila

The influence of microwave radiation (λ = 3.8 mm, intensity P = 0.1 mW/cm2) on stocks and hybrids of Drosophila melanogaster was investigated. Irradiation at the egg stage negatively influences the reproductive ability and output of the imago, and induces significant changes in the eye pigmentation of the imago. The effect of radiation depends on the state of polarization of the radiation. Linearly polarized radiation and left circularly polarized radiation induce a decrease of pigmentation, right circularly polarized radiation induces an increase of it. As the amount of the pigment is connected with manifestation of the transinactivation effect and the reinforcement of the transinactivation effect is connected with an increase of the conjugation of homologous chromosomes, the authors draw the conclusion that left polarized radiation and linearly polarized radiation cause the reinforcement of the transinactivation effect. The authors suppose that the observed effect is connected with an increase of chromosome conjugation in the interphase nucleus; the action of the right circularly polarized radiation is connected with a reduction of the effect of transinactivation that, in its turn, is connected with a reduction of the conjugation of homologous chromosomes in the interphase nucleus

Drosophila melanogaster viability and mutability under the influence of low energy microwave monochromatic and ultra wideband impulse field

The influence of microwave radiation (int = 35 GHz, intensity P = 30, 70, 180, 265 mW /cm2) and ultra wideband irradiation at irradiation intensity of 10-5, 10-4, 10-3, and 10-2 W/cm2 on stocks of Drosophila melanogaster was investigated. Irradiation was performed on the stage of egg < exposure time was 10 sec... Irradiation by monochromatic radiation (35 GHz) of intensity 70, 180 and 265 mW/cm2 negatively influences upon the viability of Drosophila. No viability decrease registered after ultra wideband irradiation. Monochromatic microwave radiation induced dominant lethal mutations (DLM). The effect of radiation depends on state of polarizations of radiation. Linear polarized radiation and right circular polarized radiation induce more DLM than left circular polarized radiation. Ultra wideband .impulse radiation induced no significant decrease of Drosophila viability. Incidence of DLM increased after ultra wideband impulse irradiation at the intensity 10-4 and 10-2 W/cm2

Effects of differently polarized microwave radiation on the microscopic structure of the nuclei in human fibroblasts

To investigate the influence of microwave radiation on the human fibroblast nuclei, the effects of three variants of electromagnetic wave polarization, linear and left-handed and right-handed elliptically polarized, were examined. Experimental conditions were: frequency (f) 36.65 GHz, power density (P) at the surface of exposed object 1, 10, 30, and 100 µW/cm2, exposure time 10 s. Human fibroblasts growing in a monolayer on a cover slide were exposed to microwave electromagnetic radiation. The layer of medium that covered cells during microwave exposure was about 1 mm thick. Cells were stained immediately after irradiation by 2% (w/v) orcein solution in 45% (w/v) acetic acid. Experiments were made at room temperature (25 °C), and control cell samples were processed in the same conditions. We assessed heterochromatin granule quantity (HGQ) at 600× magnification. Microwave irradiation at the intensity of 1 µW/cm2 produced no effect, and irradiation at the intensities of 10 and 100 µW/cm2 induced an increase in HGQ. More intense irradiation induced more chromatin condensation. The right-handed elliptically polarized radiation revealed more biological activity than the left-handed polarized one

Regularities in the E. coli promoters composition in connection with the DNA strands interaction and promoter activity

The energy of interaction between DNA strands in promoters is of great functional importance. Visualization of the energy of DNA strands distribution in promoter sequences was achieved. The separation of promoters in groups by their energetic properties enables evaluation of the dependence of promoter strength on the energetic properties. The analysis of groups (clusters) of promoters distributed by the energy of DNA strands interaction in −55, −35, −10 and +6 sequences indicates their connection with the transcriptional activity