Accumulation, functional and antioxidant responses to acute exposure to Di(2-ethylhexyl)phthalate (DEHP) in Mytilus galloprovincialis.

Mussels were exposed to di-(2-ethylhexyl) phthalate (DEHP) (0.4 mg L-1 and 4.0 mg L-1) for 24 h and 48 h and its effect on hemocyte cellular composition and spontaneous reactive oxygen production (ROS) levels in hemocytes were evaluated. Exposure to DEHP induced a loss in spontaneous ROS production levels in hemocytes and decreased agranulocyte number in hemolymph. DEHP was found to accumulate in hepatopancreas of mussels and this process was associated with an increase of catalase (CAT) activity after 24 h incubation. At the end of the experimental period (48 h) CAT activity recovered up to control levels. Superoxide dismutase (SOD) activity in hepatopancreas increased following 48 h exposure to DEHP. The results indicated that DEHP could affect hemocyte immune properties, and also cause non-specific general stress-response of the antioxidant complex, which, in turn, was not associated with pronounced oxidative stress.

[Is the coherence of low-intensity laser light essential for its effect on biological objects?]. / Sushchestvenna li kogerentnost' nizkointensivnogo lazernogo sveta pri ego vozdeistvii na biologicheskie ob''ekty?

Low-intensity laser light coherence is considered in relation to biological objects under normal physiological conditions. Estimations show that the excitation rate (the rate of coherent states generation) of typical biomolecules in visible range (sigma abs = 10(-17) cm2, I = 10(-3) W/cm2) is 10(12)-10(13) times lower than that of their phase relaxation. It means that the role of coherent interaction processes is negligible. This conclusion is confirmed by the experimental results obtained with living cells of different types.

[Effect of pulse laser UV-radiation on proliferating and resting HeLa tumor cells]. / Vozdeistvie impul'snogo lazernogo UF-izlucheniia na proliferiruiushchie i pokoiashchiesia opukholevye kletki HeLa.

Low-intensity pulse-periodic UV-radiation (lambda = 271.2 nm) within a definite repetition frequency interval (about 10 kHz and 22 kHz) and doses ranging from 0.1 to 10 J/m2 has a selective action on resting HeLa cells. In the same conditions, continuous UV-radiation (lambda = 270 nm) as well as powerful single picosecond pulses (lambda = 266 nm) do not affect the resting cells. The response of proliferating and resting cells to these types of irradiation in different.

[Growth kinetics of HeLa tumor cells during subculturing after irradiation with low-intensity red light in the stationary growth phase]. / Kinetika rosta opukholevykh kletok HeLa pri subkul'tivirovanii posle oblucheniia nizkointensivnym krasnym svetom v statsionarnoi faze rosta.

The curves of relative growth rate of HeLa cells were studied after their irradiation at the stationary growth phase (He-Ne laser, lambda = 632.8 nm, D = 100 J/m2) and reinoculation to the fresh medium in different periods after the irradiation. The irradiation evokes changes in cells of the stationary phase which are realized in subcultivation. When the interval between irradiation and inoculation is short (5 min), the cell growth is inhibited; when the interval becomes longer (up to 4 h), the cell growth in the exponential phase increases. In the HeLa cell culture with the stimulated growth only a part of cells are able, to reach the stationary growth phase.

[Effect of low-intensity periodic-impulse laser UV radiation on the nucleic acid synthesis rate in proliferating and resting cells]. / Vliianie nizkointensivhnogo impul'sno-peridicheskogo lazernogo UF-izlucheniia na skorost' sinteza nukleinovykh kislot v proliferiruiushchikh i pokoiashchikhsia kletkakh.

A study was made of the effect of the low intensity (10(-6)--10(3)/cm3) high repetition rate (pulse duration 18 nseconds, repetition rate 10 KHz) UV radiation (2nd harmonic of Cu vapour laser, lambda = 271.2 nm) on proliferating and resting cells (HeLa and fibroblast-like cells of Chinese hamster 431). The treatment within the dose range from 0.05 to 5 J/m3 stimulates DNA synthesis in the resting cells rather than in the proliferating ones. It was shown autoradiographically that, within the same dose range, the number of synthesizing cells increased in 2.5 hour.