Changes in the immune status parameters and their correction in various forms of tick-borne encephalitis]

Comparative investigation of immune status indices in patients with fever form of vernal encephalitis (group 1), with inapparent form with prolonged antigenemia (group III) and with short-term antigenemia (group II) was performed for the first time. Total 99 patients were under investigation. It was shown that in group I selective damage of immune system at T-level took place. In patients of group III immune system at all levels was less involved and humoral factor were changes. In patients in group II no significant change in immune system were registered. Activity of different immune correctors (thimalin, 4-iodoantipirine, leukinferon) was investigated in vitro. This preparations had stimulating effect in blood samples of patients with decreased immune status. In the patients with unchanged immune status no effect was demonstrated. The most prominent effect was revealed in the case of 4-iodoantipirine--interferon inducer.     

Effects of stress on psychophysiological parameters of electricity distribution network controllers in Ukraine

The purpose was to reveal the effects of stress on the parameters of cognitive performance and cardiovascular system activities in controllers working 12-hour shifts. Sixteen controllers were studied, and altogether 384 subject observations were acquired. A 5-point scale was used to estimate the perceived level of stress experienced by the controllers. Increased heart rate and heart activity-related haemodynamic parameters were found with an increase in perceived stress. Decreases found in heart rate, circulatory minute volume, and Kerdo's vegetative index over the shift became less pronounced with increased stress. Better attention was found under the average level of stress that was found on the first day shift. An effect of stress on short-term memory was not revealed. As a whole, the most pronounced changes were found during the first day shift and less pronounced changes appeared during the first night shift. Effects of stress were not found in changes of the studied parameters during the second consecutive day or night shift. Thus, increased stress causes the activation of some psychophysiological functions (attention and cardiac activity) that are indispensable for high work efficiency under increased production demands. However, the necessary activation could not be maintained during the second consecutive 12-hour shifts, probably because of accumulated fatigue, and also night work. On the other hand, too high stress may lead to the excessive activation of cardiac activity and deterioration of attention.     

Comparative analysis of rhythmic parameters of the body temperature in humans measured with thermistors and digital thermometers

In this paper we compare rhythmic parameters of human body temperature simultaneously measured with digital thermometers and thermistors with memory (Thermochron iButtons®). Thirteen healthy male and female volunteers (mean age of 25) measured oral and axillary temperatures with digital thermometers every hour during wakefulness for two days and every three hours for three days, totalling five consecutive days. Concomitantly, they wore badges with thermistors in the thorax and the wrist. Temporal series circadian rhythmicity was evaluated with the Cosinor technique. Acrophases average were 17:32 h±2:02 h for axillary temperature, 10:12 h±7:26 h for thoracic temperature, 17:18 h±00:50 h for oral temperature and 4:15 h±1:55 h for wrist temperature. The rhythmic parameters of the wrist are more robust than those of the thorax. The collection of data in humans, generally performed with digital thermometers, is restricted to the waking phase and depends on the discipline of the volunteers. We suggest that the use of the thermistor with memory in the wrist can be adopted as alternative methodology to studies of human body temperature rhythmicity, especially recommended for long temporal series.     

The properties and interrelationships of various force-time parameters during maximal repeated rhythmic grip

The purpose of this study was to examine the properties and interrelationships of various force-time parameters including the inflection point for the rate of decline in force during a maximal repeated rhythmic grip. Fifteen healthy males (age M=21.5, SD=2.1 yr, height M=172.4, SD=5.7 cm, body mass M=68.2, SD=9.2 kg) participated in this study. Subjects performed a maximal repeated rhythmic grip with maximal effort with a target frequency of 30 grip.min(-1) for 6 min. The force value decreased linearly and markedly until about 70% of maximal strength for about 55 s after the onset of a maximal repeated rhythmic grip, and then decreased moderately. Because all parameters showed fair or good correlations between 3 min and 6 min, they are considered to be able to sufficiently evaluate muscle endurance for 3 min instead of 6 min. However, there were significant differences between 3 min and 6 min in the integrated area, the final force, the rate of the decrement constant (k) fitting the force decreasing data to y=ae(-kx)+b and the force of maximal difference between the force and a straight line from peak force to the final force. Their parameters may vary generally by the length of a steady state, namely, a measurement time. The final force value before finishing and the rate of the decrement constant (k) reflect the latter phase during a maximal repeated rhythmic grip. Although many parameters show relatively high mutual relationships, the rate constant (k) shows relatively low correlations with other parameters. We inferred that decreasing the time until 80% of maximal strength and the amount of the decrement force for the first 1 min reflect a linear decrease in the initial phase.     

The effect of a high-intensity radiation exposure on the brain function of monkeys. The postradiation changes in the EEG response to rhythmic photostimulation]

In experiments with monkeys (Macaca fascicularis) it has been shown that whole-body irradiation with a dose of 45 Gy (6.5 Gy/s) causes considerable changes in the EEG response to rhythmic photostimulation (PS). These changes are: reduction of the desynchronizing effect of PS with regard to a background rhythmicity; decrease in the reception rate of the rhythms of light flashes (RLF); narrowing of the RLF frequency range; and increase in the reaction momentum. The postirradiation changes in the EEG response to PS are considered as a manifestation of inhibition of the cortex functional activity and impairment of sensory information processing in the brain.     

Effects of various taste stimuli on heart rate in humans

Relationships between taste stimuli and heart rate were evaluated in 29 healthy university students. The test solutions were sucrose, NaCl, citric acid, quinine-HCl and monosodium glutamate (MSG). Heart rate increased by 7.1-13.6% for all the taste stimuli after use as compared with pre-stimuli values. The maximum increases in heart rate came approximately 25 s after the taste stimuli. After the increases, heart rate returned to pre-stimuli levels after between 80 and 100 s. Heart rate reached its maximum with citric acid. Recovery from the heart-rate increase was more delayed for quinine-HCl and MSG than for the other stimuli. Except for sucrose, increases in heart rate and the hedonic scale values of the taste solutions showed significant negative correlation. These findings show that the taste stimuli solutions increased the heart rate and that the increase differed with the concentration and taste solution used.     

Effects of fatigue on the temporal neuromuscular control of vastus medialis muscle in humans

The effects of muscle fatigue on the temporal neuromuscular control of the vastus medialis (VM) muscle were investigated in 19 young male subjects. The electromyogram (EMG) activities of VM and the force generation capacities of the quadriceps muscle were monitored before and after a fatigue protocol. In response to light signals, which were triggered randomly, the subjects made three maximal isometric knee extensions. This was then followed by the fatigue protocol which consisted of 30 isometric maximal voluntary contractions at a sequence of 5-s on and 5-s off. Immediately after the exercise to fatigue, the subjects performed another three maximal isometric contractions in response to the light signals. The effects of fatigue on the temporal neuromuscular control were then investigated by dividing the total reaction time (TRT) into premotor time (PMT) and electromechanical delay (EMD). The TRT was defined as the time interval between the light signal and the onset of the knee extension force. The PMT was defined as the time from the light signal to the onset of EMG activities of VM, and EMD as the time interval between onset of EMG activities to that of force generation. Following the contractions to fatigue there was a significant decrease in peak force (Fpeak, P = 0.016), an increase in the root mean square (rms)-EMG: Fpeak quotient (P = 0.001) but an insignificant change in the median frequency (P = 0.062) and rms-EMG (P = 0.119). Significant lengthening of mean EMD was found after the fatigue protocol [0.0396 (SD 0.009) vs. 0.0518 (SD 0.016) s P<0.001]. The lengthening of EMD in VM would affect the stabilizing effect of the patella during knee extension. The faster mean PMT [0.2445 (SD 0.093) vs. 0.2075 (SD 0.074) s, P = 0.042] following the fatigue protocol might have compensated for the lengthened EMD and contributed to the insignificant change in the mean TRT [0.284 (SD 0.09) vs. 0.259 (SD 0.073) s, P = 0.164]. This was probably related to the low level of fatigue (15% decrease in force) and the stereotyped nature of the action such that the effects of the fatigue on neuromuscular control were likely to have been attributable to peripheral processes.     

Changes in various parameters of the mouse immune status subjected to chronic social conflict

Recurrent experience of a social confrontation was shown to increase the per cent of cleavage nucleus neutrophiles in both mice-participants, activation of the lymphocyte dehydrogenase, and reduction of number of the CDA+ and CD8+ T-lymphocytes. Dynamic character of changes in the metabolism parameters and the number of lymphocytes is obviously dependent on duration of the confrontations in mice.     

Effects of alpha-tocopherol and related compounds on reactions involving various organic radicals

Effects of alpha-tocopherol, PMC, and a number of the respective sulfur-containing analogues on reactions involving various organic radicals were studied. The test compounds were found to interact with alkyl radicals more effectively than with peroxyl radicals. The presence of a sulfur atom in structures of the respective analogues did not produce significant effects on reactivity. Derivatives of 5-hydroxy-1,3-benzoxathiol-2-one and 6-hydroxy-1,4-benzoxathiin-2(3H)-one displayed a high reactivity toward alpha-hydroxyalkyl radicals.     

Effect of expiratory muscle fatigue on exercise tolerance and locomotor muscle fatigue in healthy humans

High-intensity exercise (> or =90% of maximal O(2) uptake) sustained to the limit of tolerance elicits expiratory muscle fatigue (EMF). We asked whether prior EMF affects subsequent exercise tolerance. Eight male subjects (means +/- SD; maximal O(2) uptake = 53.5 +/- 5.2 ml.kg(-1).min(-1)) cycled at 90% of peak power output to the limit of tolerance with (EMF-EX) and without (CON-EX) prior induction of EMF and for a time equal to that achieved in EMF-EX but without prior induction of EMF (ISO-EX). To induce EMF, subjects breathed against an expiratory flow resistor until task failure (15 breaths/min, 0.7 expiratory duty cycle, 40% of maximal expiratory gastric pressure). Fatigue of abdominal and quadriceps muscles was assessed by measuring the reduction relative to prior baseline values in magnetically evoked gastric twitch pressure (Pga(tw)) and quadriceps twitch force (Q(tw)), respectively. The reduction in Pga(tw) was not different after resistive breathing vs. after CON-EX (-27 +/- 5 vs. -26 +/- 6%; P = 0.127). Exercise time was reduced by 33 +/- 10% in EMF-EX vs. CON-EX (6.85 +/- 2.88 vs. 9.90 +/- 2.94 min; P < 0.001). Exercise-induced abdominal and quadriceps muscle fatigue was greater after EMF-EX than after ISO-EX (-28 +/- 9 vs. -12 +/- 5% for Pga(tw), P = 0.001; -28 +/- 7 vs. -14 +/- 6% for Q(tw), P = 0.015). Perceptual ratings of dyspnea and leg discomfort (Borg CR10) were higher at 1 and 3 min and at end exercise during EMF-EX vs. during ISO-EX (P < 0.05). Percent changes in limb fatigue and leg discomfort (EMF-EX vs. ISO-EX) correlated significantly with the change in exercise time. We propose that EMF impaired subsequent exercise tolerance primarily through an increased severity of limb locomotor muscle fatigue and a heightened perception of leg discomfort.