Promising Gene Delivery Properties of Polycations Based on 2-(N,N-dimethylamino)ethyl Methacrylate and Polyethylene Glycol Monomethyl Ether Methacrylate Copolymers

Cationic copolymers based on 2-(N,N-dimethylamino)ethyl methacrylate and polyethylene glycol monomethyl ether (pDMAEMA-co-PEO) with different molecular weights have been synthesized. Their physicochemical properties were studied by NMR spectroscopy, sedimentation, and potentiometric titration. According to the data of potentiometric titration for the synthesized pegylated cationic copolymers, the apparent dissociation constants were determined in the pH range from 4.5 to 8.5. The physicochemical properties of interpolyelectrolyte complexes of these polycations with circular DNA (IPEC DNA) were also studied by dynamic light scattering, electrophoretic mobility, and TEM methods. It has been established that the diameter and electrokinetic potential (ζ-potential) of interpolyelectrolyte complexes can be varied over a wide range (from 200 nm to 1.5 μm and from -25 mV to +30 mV) by changing the ratio of oppositely charged ionizable groups in pegylated cationic copolymers and DNA, as well as by regulating medium pH. The resistance of the IPEC DNA/polycation complex to the action of nucleases was studied by electrophoresis in agarose gel; the cytotoxic effect of the polymers in vitro, and the efficiency of penetration (transfection) of IPEC DNA with PDMAEMA-co-PEO-polycations into eukaryotic cells of a cell line derived from human embryonic kidneys HEK 293 in vitro.

[Seasonal dynamics of physiological parameters in the elderly men living in the European North of Russia.]

The study of physiological processes in the elderly people, especially in the chronobiological aspect, is of current interest. The subjects of the study were a group of elderly people (n=18, middle age 69,3±6,5 years), inhabitants of nursing house (Syktyvkar, 61о 04″ NL), who were surveyed 4 times within a year. The aim of the work was to study the dynamic of physiological parameters (anthropometric, cardio-respiratory, psychophysiological, e.t.c.) of elderly people at in different seasons of the year in the European North of Russia. Our results showed that, living conditions and age-related changes in organism modify the amplitude of seasonal changes of the physiological parameters.

[The application of the emulsified turpentine baths for the correction of the functional state of the cross-country skiers]

The baths with emulsified turpentine find the wide application in balneotherapy. They produce especially pronounced beneficial prophylactic effects in the patients presenting with microtrombosis and microvascular stasis. Moreover, these baths may be prescribed to improve microcirculation, increase the functional reserves and physical capacity in the athletes. At the same time, the current literature appears to contain no scientific publications on the application of emulsified turpentine baths for the restoration of the physical capacity of the professional ski runners. The lack of relevant information motivated the study reported in the present article. The main objective of the study involving 10 subjects was to evaluate the effectiveness of the modified emulsified turpentine baths as a method by which to restore and enhance the physical capacity of the professional cross-country skiers. The physical capacity of the athletes was evaluated from the results of the bicycle ergometer exercise test with the use of the «Oxycon Pro» system. The data obtained suggest that a course of the emulsified turpentine baths increases the activity of the cardiorespiratory system, improves the physical capacity, and enhances the functional reserves of the body in the anaerobic zone.

[Influence of latitude factor on organism of adolescences residing on North]

Complex investigations of adolescences (14-15 years) residing on the European North at 62 and 65 degrees latitudes have been carried out. It was shown that the latitude factor on the North affected on mature organism of adolescences already at a difference of residence place on 3 degrees. The decrease of tolerance to hypoxemia, quality of hemodynamic regulation at short-term physical activity, physical health level, nervous processes rate (switching of attention) and the increase of plasma lactate level (attribute of hypoxia) were shown in adolescences residing at higher latitudes. The sexual distinctions and features of northerner organism on a lot of parameters in adolescences were revealed.

[Physiological and psychophysiological indices dynamics in operators with three-shift working day in different working conditions]

It was shown that intense operator work in pulp and paper industry (bleachers and chlorinators) with changes in shift time (day, evening, night) causes fatigue. The fatigue in operators was indicated by increasing number of errors in sensomotor coordination test and coordination index, and among chlorinators it was accompanied by deterioration of state of health. Manifestations of 24 hours' rhythm of physiological functions were detected by changes in body temperature (among bleachers), heart rate, blood pressure and sensomotor coordination indices (all operators). Harmful chemical substances (chlorine and chlorine dioxide) in the air negatively influence psychophysiological status among clorinators.

[Rated power of conscripts in the north]

The nutrition on alimentary and power value in the term active duty soldier on the North on norm No 1 (troop ration) approaches to calculated sizes (with the exception of fat deficiency) that allows to support the physical working capacity and the body mass index on high enough level. However insufficient content of vitamins (polyhypovitaminosis) in organisms of most of studied persons was revealed. The dynamics of change of nutrition status in the soldiers on the North during year shows essential dependence on the weather rigidity parameters and the seasonal factor.

[Functional state during working shift in workers exposed to occupational hazards in cellulose production]

The authors demonstrated role of chemical factor determining workers' psychophysiologic state at work, defined influence of work conditions jeopardy degree on body functions before and during the working shift in contemporary cellulose production.

[Seasonal aspects of the oxidative stress in Northeners]

Evaluated were consequences of changes in oxygen demand, bronchial conduction, exercise performance, functioning of antioxidant enzymes and body provision with natural oxidants for the level of free-radical oxidation products in human organism. To this end, a group of essentially healthy young male northerners spending much time outdoors was surveyed over a one-year period. Among the listed parameters oxidation of free radicals was particularly sensitive to seasonal insufficiency of some of the antioxidant enzymes.

[Functional characteristics of the cardiovascular system of old people--inhabitants of the north]

The electrocardiographic investigation of healthy old people from three ethnic groups of natives of the Komi Republic at the age of 80+ years revealed increase of QRS-complex, enlargement P-Q and Q-T intervals duration, decrease of amplitude of T-wave. This testifies to age-associated lowering of the depolarization processes in myocardium, increase of atrio-ventricular conductivity and compensative extension of repolarization period. We determined the predominance of the left direction of ORS axis in old people. The increase of amplitude of mode of R-R intervals (AMo 50-90%), low range of variation of cardio intervals characterize heart rate stability in 60% of subject, indicate the limitation of sinus node lability and decrease of cortex component in regulation of cardiac rhythm. These processes in old people are adaptive ones to reduce redundant stress of heart capacity in extreme conditions. Normotensive people amounted more than 50% of investigated Northern Komi (SBP 125 +/- 13, DBP 72 +/- 8 mmHg). In groups of Russian women and Southern Komi the prevalence of hypertension revealed itself and it reached in average 170/97-174/87 mmHg.

[Effects of the factor of season on the the physiological status of petroleum industry workers in the Polar region]

There were three medical examinations (in March, June and October) of oilers on shift days 5-6 in a field medical post in the Polar region. The survey protocol included analysis of morning (before breakfast) biochemical and cell indices, physiological examination, testing reactions to standard stimuli (color, tone), psychological testing, assessment of factual nutrition, analysis of the cardiorespiratory function at rest and during physical tests. It was stated that recovery of physical performance varied with the seasons. In March, the shift workers were significantly less reactive to the color stimulus. At low ambient temperature (-38 degrees C) blood content of alpha 1- and alpha 2-globulins went up, and there were atypical proteins and considerable amounts of total cholesterol, pre-beta-lipoproteins and alpha-lipoproteins in blood.