Visnyk of Dnipropetrovsk University. Biology, medicine

8-12

Authors: T. V. Martyshuk

This article presents the results of research on the influence of oxidative stress on the intensity of the process of lipid peroxidation and the activity of the glutathione system of antioxidant defense in the organisms of rats. Intramuscular injection of 50% solution of tetrachloromethane at a dose of 0.25 ml per100 gof body weight to rats from the experimental group causes activation of the process of free radical lipid oxidation with excessive accumulation of intermediate anf final products of lipid peroxidation. The research results indicate that the development of oxidative stress leads to significant and probable acceleration of the formation and accumulation in the plasma of the rats, in all stages of the experiment, of lipid hydroperoxides and malonic dialdehyde. The highest level of hydroperoxides of lipids in the blood plasma of rats under oxidative stress was on the second day of the experiment, where it was 843 unE/ml, whereas in the control this index was 0.245 unE/ml. During the research into the content of malondialdehyde it was found that in the experimental group of animals it was 2.03 times higher than in the control group on the 5th day. On the 10th and 14th days of the experiment we observed a slight reduction in the levels of lipid hydroperoxides and malondialdehyde. The development of oxidative stress also leads to inhibition of the glutathione system of antioxidant defense in the rats’ organism. This shows the low activity of glutathione peroxidase and the low level of restored glutathione in the blood of the rats from the experimental group. On the 5th day of experiment the activity of glutathione peroxidase and restored glutathione level in the blood of the rats which were injected with carbon tetrachloride was at its lowest, compared with the control these indices decreased respectively by 53% and 51%. On the 10th and 14th days of the experiment the activity of glutathione peroxidase and restored glutathione level in the blood of the rats from the experimental group were slightly increased, but compared to the control they were still significantly lower. Significant disturbances were found in the oxidation-antioxidant balance of the animals under oxidative stress, which is characterized by the activation of the processes of free radical lipid oxidation with excessive accumulation of intermediate and final products and the inhibition of the antioxidant defense system.

18-26

Authors: T. O. Tretiak, O. V. Severynovska, M. Boyko

The contents of education must correspond not only to the level of knowledge and competencies, but also be directed to self-determination of the personality and creation of conditions for its self-development and self-realization. The aim of this study was to identify the psycho-physiological peculiarities of Biology students and to establish the connection between the students’ academic performance, their cognitive abilities and their psycho-physiological characteristics, which is essential for improving the academic process and bringing it to the high level of professional education necessary for graduates of higher educational establishments to compete successfully in the job market. It was established that the majority (46%) of Biology students are ambiverts, 34% of them are extroverts, and 18% – introverts. There is a statistically reliable connection between the academic grades and the personality type: the more successful students are ambiverts and introverts. Extroverts demonstrate lower academic results. According to different types of asymmetry manifestation among Biology students, the right-handed accounted for 35% of the tested, those with prevailing right hand – 51%, those with prevailing left hand – 1.2% and the left-handed – 12%. There is no dependence of academic performance on the asymmetry manifestation. Most Biology students have a sanguine-choleric temperament and slightly expressed or absent asymmetry, which testifies to the power of nervous processes and is a precondition for successful studying. The majority of students, irrespective of the academic performance level, have a low level of stress resistance and a medium level of personality anxiety. Students who score A and B points for academic performance, have a medium level of situational anxiety. Those who score C points have a high level of anxiety. There is no connection between the academic points and personality anxiety level, but there is significant connection between academic performance and situational anxiety. There has been established a significant dependence of academic performance on the level of situational anxiety: introverts and extroverts have a high level, ambiverts have a medium level of situational anxiety. Introverts and ambiverts with a low and medium anxiety level demonstrate higher academic performance. Extroverts with a high anxiety level find it more difficult to study. The majority of Biology students have a high level of visual-imaginative, object-active and creative thinking types. 83% of students have a high and a medium level of verbal-logical thinking type. Abstract-symbolic and intuitive thinking are developed in lesser degree. There has been established a reliable negative correlative connection between object-active thinking type and introversion, and a positive connection between intuitive thinking and introversion, irrespective of academic results. The more introversion is expressed, the more intuition is developed. Academically successful students demonstrated a positive correlation between the abstract-symbolic thinking type and introversion. Extroverts with low academic performance don’t have significant correlation connections with the thinking types, whereas it is characteristic for academically successful students to demonstrate a higher level of visual-imaginative, verbal-logical, abstract-symbolic and creative thinking along with an increase in demonstrating extroversion. Practically all thinking types (except for the object-active) are more fully expressed in successful ambiverts; the manifestation of a certain thinking type increases while ambiversion increases. Less academically successful students have a reliable correlative connection between ambiversion and visual-imaginative, abstract-symbolic and creative thinking. Performance of tasks connected with all thinking types irrespective of typological characteristics of students was accompanied by a reliable increase in saturation. More diversified reactions in the process of thinking activity were observed in the cardio-vascular system: introverts and ambiverts who demonstrated high results in the tests, showed significant decrease of heart beat rate in the process of intuitive and visual-imaginative thinking. Extroverts who demonstrated low results in the tests, by contrast, showed an increase in heart beat rate. When students of all typological groups were doing tasks connected with verbal-logical thinking, their heart beat rate significantly increased. Ambiverts and introverts were more successful. Thus, the whole range of psychological and physiological characteristics of a person defines his successful academic performance and real activity.

32-36

Authors: G. A. Al-Maali, N. A. Bisko, A. M. Ostapchuk

The aim of our research was to study the influence of citrate and sulfate of copper, manganese and zinc on the carbohydrates composition of biomass of the medicinal mushroom Trametes versicolor (L.) Lloyd. cultivated in a liquid medium. The studied strain of Trametes versicolor 353 was obtained from the Culture Collection of Mushrooms (IBK) from the M. G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine. Citrates of copper, manganese and zinc were obtained from the Institute of Nanobiotechnologies and Resource Conservation of Ukraine, Kyiv. In this study we used glucose-peptone-yeast extract medium (GPY) with the following composition of (g/L): glucose – 25, peptone – 3, yeast extract – 3, K2HPO4 – 1, KH2PO4 – 1, MgSO4 ∙ 7H2O – 0.25, distilled water – 1,000 ml; pH 6,5 (control medium). Cu2+ (sulfate form or citrate form) were added to control medium in concentration 4 mg/L, Zn2+ and Mn2+ (sulfate form or citrate form) were added to control medium in concentration 1 mg/L. Mycelium was grown in a submerged culture on a rotary shaker (120 rpm) at 26 °C in 250 ml Erlenmeyer flasks, containing 50 ml of liquid medium. The biomass was harvested after 9 days of cultivation in the liquid medium. Monosaccharides and sugar alcohols was analyzed by high-performance liquid chromatography Agilent 1200 (Agilent technologies, USA). The results of our research demonstrated that the fraction of total carbohydrates from T. versicolor 353, which were cultivated on the control medium, consists of glucose (91.5%), galactose (1.9%), mannose (5.4%), fucose (0.6%) and xylose (0.7%). The adding of sulfate of zinc or copper to the liquid medium didn’t change the content of monosaccharides of T. versicolor 353 biomass relative to the control medium. At the same time, in the medium with citrate of zinc the amount of glucose increased and the amount of mannose decreased relative to the control medium. Xylose and fucose were not detected in this case. In mycelium of T. versicolor 353 that was cultivated in the medium with manganese sulfate or manganese citrate we detected a small amount of ribose. But the content of other monosaccharides didn’t change in the medium with sulfate of manganese. At the same time, the addition of citrate of manganese to the medium raised the amount of mannose and reduced the amount of glucose in the biomass of T. versicolor 353 relative to the control medium. Also copper citrate reduced the content of glucose in mycelium of T. versicolor 353 relative to the control medium. But in this case we detected mannitol and sorbitol in the biomass. This data indicates that synthesis of sugur alcohols in T. versicolor 353 depend on copper ions in bioactive forms of citrate.

43–47

Authors: E. Z. Ivanchenko

In studies on healthy humans we examined changes in the H reflex amplitude and the intensity of background EMG of the soleus muscle within the premotor period of voluntary extension of the contralateral ankle joint. The tested persons were in the lying prone position with relaxed legs, or in the standing position with support on both feet or only on one foot with additional hand support. The soleus H reflex was induced using the standard technique by transcutaneous stimulation (1 ms long current pulses) of the tibial nerve afferents in the region of the popliteal dimple. Using superficial electrodes, we recorded the integral EMG reflex discharge from the m. soleus, amplified, and visualized it using a two-channel digital oscillograph, Handiscope HS3 (TiePieEngeneering, Netherlands). In other tests, we also recorded tonic background EMG activity from the soleus muscle. After fullwave rectification and low-frequency filtration we estimated the area under the integral curve enveloping oscillations of the above mentioned EMG. In the lying position the extension of contralateral ankle joint evoked anticipatory facilitation of the testing soleus H-reflex. It manifested in 90–60 ms and reached the maximum 30 ms before the conditioning movement. Considerable changes of the soleus background EMG-activity did not occur during the premotor period. Consequently, it is supposed that the mechanism leading to the H-reflex facilitation is the decrease of presynaptic inhibition at 1a. In the standing position with support on both feet contralateral ankle joint extension caused anticipatory inhibition of the soleus H-reflex and simultaneous suppression of background EMG 90–60 ms before the conditioning movement. These results indicate the anticipatory changes of muscle tone and suggest participation of postsynaptic mechanism in the inhibition of the testing H-reflex. When the moving contralateral extremity had no support, the contralateral ancle joint extension did not cause anticipatory inhibition but facilitation of the soleus H-reflex. Its time course was similar to that observed in the lying position. The considerable changes of the soleus background EMG-activity did not arise. The results of the experiments indicate that the nature of premotor changes in the spinal neuron circuits, associated with the lower limb muscles, depends not only on the type of upcoming voluntary movement. Being caused by the contralateral limb movements, they depend greatly on the fulfillment or nonfulfillment of the support function by the lower limbs.

53–58

Authors: V. P. Zhalko-Tytarenko, E. A. Synetar, S. I. Savoschenko

It is well known that the ureter of mammals and man works as a flow system that normally remains uninfected. In biotechnology flow systems are used to produce microbial mass on orders greater than when grown in laboratory and industrial periodic cultures. Therefore, these systems are used in the microbiological industry. But there ina flow systems one can observe a growth in microbial populations, the patterns of which can be fruitful in studying the process of catheter-associated urinary tract infections. The main factors are the speed of propagation and speed of flow, and their variation in conditions of the catheterized urinary tract, which determines the magnification factor of microbial infection. In this lies the general biological need to study them from a biotechnology perspective. Hence the question arises – why are there changes in the flow system of the urinary tract during catheterization, which contribute to the reproduction of opportunistic microorganisms, as a factor of infection? In the study of the biological properties of agents of catheter-associated infections this issue has not attracted sufficient attention from researchers. In view of the above, the purpose of our study was to establish patterns of population growth of agents of urinary tract infections on the model of the yeast fungus species Candida albicans (C.P. Robin) Berkhout, 1923 in the catheterized human urinary tract, treated as a flow system. The results of the research show that the emergence of catheter-associated urinary tract infections is a regularity inherent throughout the flow system. It was proved that with the model C. albicans, bacteria in urine multiply faster than in the medium Saburo. The study established that one of the factors leading to catheter-associated urinary tract infections is the persistent presence of urine deposits around the head of the catheter in the bladder, which provides bacteria with sufficient conditions for reproduction and where bacteria cannot be eliminated by urine flow. When the pathogen enters and reproduces in the bladder, the latter is a reservoir of infection like a "royal culture", with a gradual overgrowth in the catheter of yeast fungi of the species C. albicans. These data suggest that the mechanism of strengthening catheter-associated urinary tract infections are the formation of biofilms by microorganisms around the catheter head and on its surfaces. It is recommended to further improve the design of urinal catheters in such a way that ensures the complete emptying of the bladder and avoidance of urethral reflux.

65–70

Authors: A. G. Morenko

An important component of the general biological problem of coordinated activity of the brain’s motor systems and of the executive apparatus during the implementation of motor functions is the question of the interconnection of electroencephalogram (EEG) rhythm characteristics, above all α-rhythm, with control peculiarities of manipulative movements (MM). A test group consisting of 113 healthy right-handed women from the ages of 19 to 21 was divided into two groups according to the average magnitude of their individual modal α-frequency – groups with high and low values of individual modal α-frequency (IαF). The ideal time of a simple sensorimotor reaction and choice-point behavior as well as speed capabilities of nervous processes during the finger tapping test, and measures of the power spectrum of ЕЕG spectral components individually determined for each testee in quiescent intervals and while performing alternating movements by the fingers of the right hand were evaluated. Alternate female finger movements were accompanied by a decrease in the EEG α2- and α3-activities in the posterior cortical areas, and β1- and γ-activities in the frontal, temporal and central areas of the cortex compared with the same in the immobile state; they were also characterized by the generalized growth of θ-oscillations and local (in the frontal leads) – α1- and β2-activities. Thus, in both groups of women surveyed the increase in activity of those cortical structures that ensure its implementation – sensory perception, motor start and motor programming commands and sense-motor coordination, was found. When MM are performed by women with a higher output α-frequency, they were characterized by more local changes in the electrical activity of the cerebral cortex. People with a lower modal α-frequency were characterized by somewhat less specific and differentiated features of the cortex activation. Alternating movements of fingers performed by women with low IαF were associated with higher EEG θ-, α1-, α2-activities, generally in the cortex, and α3-, β- and γ-oscillations – in the posterior areas than in those with high IαF. Instead of this, a relatively lower power spectral EEG was recorded in the frontal leads of the range consisting of α3-, β- and γ-oscillations. Intergroup differences found by us may indicate a higher status regarding a specific cortical tone, its readiness for activity and control of information processes in people with high IαF in comparison with those who had low IαF. It is natural that different levels of features of such activation systems achieve specific outcomes in testees with a different starting IαF. Women with a higher IαF had better speed characteristics of nervous processes.