We studied biophysical features of interaction between 0.1 Hz oscillations in heart rate variability (HRV) and distal blood flow (DBF) variability in healthy subjects and patients after acute myocardial infarction (MI). 125 patients after acute MI (72 male and 53 female) aged between 30 and 83 years and 33 healthy subjects (23 male and 10 female) aged between 20 and 46 years were included in the study. The duration of prospective study of MI patients was one year. We estimated the delay in coupling between 0.1 Hz oscillations in H RV and DBF variability. It is found out that in healthy subjects the delay in coupling from heart rate to DBF is less than delay in coupling from DBF to heart rate. Acute MI results mainly in disruption of coupling from heart rate to DBF. This coupling is partially restored in one year after acute MI, but the delay in coupling remains significantly smaller than in healthy subjects. The features of coupling from DBF to heart rate are restored in MI patients within three weeks after infarction. After this period the delay in this coupling in MI patients is approximately the same as it is in healthy subjects.
Velocity changes in the solar wind, recorded by satellite (IMP8 and Wind) are characterized by a solar cycle dependent approximately 1.3-year component. The presence of any approximately 1.3-year component in human blood pressure (BP) and heart rate (HR) and in mortality from myocardial infarction (MI) is tested and its relative prominence compared to the 1.0-year variation.
Around the clock manual or automatic BP and HR measurements from four subjects recorded over 5 to 35 years and a 29-year record of mortality from MI in Minnesota were analyzed by linear-nonlinear rhythmometry. Point and 95% confidence interval (CI) estimates were obtained for the approximately 1.3-year period and amplitude. The latter is compared with the 1.0-year amplitude for BP and HR records concurrent to the solar data provided by one of us (JDR).
An approximately 1.3-year component is resolved nonlinearly for MI, with a period of 1.23 (95% CI: 1.21; 1.26) year. This component was invariably validated with statistical significance for BP and HR by linear rhythmometry. Nonlinearly, the 95% CI for the 1.3-year amplitude did not overlap zero in 11 of the 12 BP and HR series. Given the usually strong synchronizing role of light and temperature, it is surprising that 5 of the 12 cardiovascular series had a numerically larger amplitude of the 1.3-year versus the precise 1.0-year component. The beating of the approximately 1.3-year and 1.0-year components was shown by gliding spectra on actual and simulated data.
The shortest 5-year record (1998-2003) revealed an approximately 1.3-year component closer to the solar wind speed period characterizing the entire available record (1994-2003) than that for the concurrent 5-year span. Physiological variables may resonate with non-photic environmental cycles that may have entered the genetic code during evolution.
The present paper deals with studying of hemostasis system indices in the course of the experiment with a 105-day isolation in a hermo chamber. The following values were determined: activated partial thromboplastin time, prothrombin time (PT), prothrombin index (PI), international normalized ratio [relationship] (INR), thrombin time, fibrinogen concentration, soluble fibrin-monomer complexes, D-dimer, plasminogen (PG), activity of antithrombin III, protein C, alpha2-antiplasmin. According to the experiment results, isolation is accompanied by PT prolongation (PI decreasing, INR increasing) which conserves up to the 7th day of the aftereffect period, as well as by PG concentration decreasing. Changes are likely to be connected with peculiarities of reduced motion activity conditions, compensatory physical activity influence, protein and lipid metabolism characteristics changing.
Human proteome is very plastic, it changes under the influence of various biological factors. It is of big interest to find out how specific factors of an environment, including a long-term isolation affect on urine proteome. The study was conducted during the experiment with 105-day isolation. In the present investigation we collected urine samples from 6 healthy volunteers (26-41 years old). The physical activity, daily rhythms and diet were controlled. Urine samples were fractionated on magnetic beads MB-HIC C8 (MB - hydrophobic-interaction chromatography) with ClinProt robot (Bruker Daltonics) prior to MALDI-TOF mass spectrometer analysis with Autoflex III TOF/TOF (Bruker Daltonics), working in a positive linear mode. 117 peaks have been obtained in each spectrum of urine. We have shown that even during isolation and under controlled conditions of life a high variability of urine proteome of healthy personas (36 protein MC-peaks in the urine, on average) are revealed.
EEG coherence in theta and alpha bands during set-forming and set-shifting was studied in 5-6-year-old (n=18) and 10-11-year-old (n=25) children. Set was formed to visual stimuli (facial photos with emotionally negative expression). Younger children displayed smaller coherence values, especially in the right hemisphere, than older ones. We also revealed differences in theta and alpha band coherence in cases of a rigid and a plastic set. For example, EEG-coherence values were smaller when cognitive processes were relatively rigid (i.e., in a case of a slower set-shifting). A strong correlation between electrophysiological and behavioral data supports the hypothesis that cortico-hippocampal and fronto-thalamic brain integration systems participate in facial expression recognition and provide cognition flexibility.
Estimations of hyperacuity and visual acuity (VA) have been compared in schoolchildren aged 11-17 years with normal vision. VA was measured using Landolt Cs and Tumbling Es. Hyperacuity was measured by vernier stimuli. Acuity estimations depended on the test stimuli. They were in 1.1 times over for Landolt Cs than for Tumbling Es. Hyperacuity estimations exceeded VA in 1.25-4.1 times. They were almost twice as high among pupils of 16 years compared to 13-year-olds, in contrast to estimates of VA, which practically did not change with age. Binocular VA was significantly higher monocular VA in 1.05 times regardless of age. The ratio between the binocular and monocular hyperacuity estimates for thirteen years pupils in average was equal to 1.9, while for sixteen years pupils--1.2. We discuss the contribution of binocular vision in the development of mechanisms of VA and hyperacuity in ontogenesis and the difference between these mechanisms.
Experimental physiological studies were made in 10–11-year-old boys and girls, students of a gymnasium and an education-upbringing
complex. The functional parameters recorded in children momentarily included: the heart rate, systolic and diastolic arterial
pressure, Roufier index, and the adaptation potential (AP) of the cardiovascular system as an integral index of the adaptivity
level of human organism on the whole, measured according to special formulas, and the index of the risk of disease development.
Apart from it, the height, body mass, vital lung capacity, and strength of hand grip were measured, the puberty stage and
deviations in the functioning of organs and systems were revealed. The AP levels used to evaluate adults’ adaptation did not
agree with 10–11-year-old children’s physical development degree, puberty stages, and health condition (belonging to different
health groups). No agreement was found between the levels of these parameters and the degrees of AP of the cardiovascular
system in 10–11-year-old children based on their individual values and sigmal deviations of this index. Therefore, a conclusion
on the adaptation capacities of a child’s organism and the risk of disease development in it based on the AP values may be
erroneous. The authors suggest an age scale of the AP levels for 10–11-year-old children.
Spectral analysis was performed to assess the periodic variations in the heart rate (HR), blood pressure (BP), and respiratory volume (RV) in 8- to 11- year-old children at rest. Age- and gender-related differences were revealed in the total power and spectral components of the HR, BP, and RV spectra.
Heart rate variability (HRV) was assessed each quarter during a year in 11- to 13-year-old girls with a Valenta medical diagnostic system. The HRV was highest in winter and lowest in summer (in 12-year-old girls) and autumn (in 11- and 13-year-old girls), indicating seasonal changes in the degree of β-adrenergic effects on the heart (lowest in winter and highest in summer and/or autumn). The changes were most pronounced in 11-year-old girls, i.e., at the onset of puberty. Seasonal changes in the HRV can be explained by changes in the blood levels of direct and indirect endogenous modulators of chemoresponsiveness and are considered to be a mechanism of human adaptation to external conditions.
A study of quick adaptation of the myocardium of subjects operating a computer, depending on the adaptive capacities of the
body, was conducted in 100 children with ages varying between 10 and 11 years using the electrocardiography method for the
analysis of heart rate variability. Significant differences in the bioelectrical processes in the myocardium and autonomic
nervous regulation of the cardiac rhythm (CR) were found in children with different adaptive capacities of the body. Quick
adaptation to the operator activity in children with a good adaptive capacity is characterized by intensification of atrial
activity and metabolic processes in the myocardium, as well as by a shortened duration of the cardiac cycle due to a shorter
diastolic time, determined by increased sympathetic influences on the CR. In children with a decreased adaptive capacity,
a decrease in the atrial excitability and myocardial metabolism, an increase in the systolic time, a decrease in the diastolic
time, and an increase in parasympathetic influences on the CR are observed.
Experimental physiological, psychological, and hygienic studies were conducted for three years in the same fifth to seventh
grade schoolchildren from 11 to 13 years of age. The findings made it possible to evaluate health status, the intensity of
daily academic and out-of-school loads, changes in mental work capacity (MWC), and the relationship between the MWC and other
indices of body function in the schoolchildren under study. The highest functional tension was experienced by the fifth grade
schoolchildren and can be explained by the onset of puberty and changes in both the academic load and study conditions as
compared to those at the previous stage of school education.
In work on the basis of use functional and ergometric working capacity indicators specificity of power supply of muscular activity of healthy boys of 13-14 years (n = 162) with various at puberty stages (PSs). It is established, that the boys, being on II-IV PSs, considerably differ on indicators of power, capacity and efficiency of energy systems. Three groups of the bioenergy systems indicators differing on an orientation of their changes at teenagers depending on rates of puberty stages. The first group includes the physiological variables which most considerable levels are observed at children with high rates of development. All of them concern to anaerobic alactic and anaerobic glycolytic to components of physical working capacity. The second group unites the physiological variables which highest values are marked at teenagers with average rate of development, and the least--at children with the accelerated rate of maturing. These indicators reflect, mainly, set of aerobic possibilities of an organism. The third group includes the indicators which highest levels are marked at teenagers with low rate of development, and the least--at boys with the accelerated rate of maturing. They reflect the maximum aerobic power and endurance to power work. It is revealed, that teenagers of 13-14 years with average rates of development are characterised in comparison with children with the accelerated maturing, higher indicators of power and capacity of aerobic system of energy-supply, and in comparison to teenagers to the slowed down development--lower maximum aerobic power against higher capacity and profitability of functioning of aerobic system. Adolescents with average rates of maturing surpass also schoolboys with the accelerated and slowed down development concerning capacity of work in mixed anaerobic-aerobic a mode. In turn boys of 13-14 years with the accelerated development differ from schoolboys with the average and slowed down rates of maturing, high anaerobic productivity of an organism, rather low aerobic possibilities and increase of a tone of parasympathetic department of autonomic nervous system (AHC). The given circumstance is necessary for considering at realisation of the differentiated approach to rationing of loadings in the course of physical education and sports training of adolescents of 13-14 years.
Visual acuity (VA) in 292 schoolchildren aged 8–17 years was measured using Landolt Cs, E letters, and rectangular gratings. With the forced choice procedure, the VA measured with Landolt Cs was 1.4 times higher than with other targets, suggesting analysis of the whole image rather than its gaps by the visual system. In addition, the effect of surrounding images on VA estimates was studied with Landolt Cs, E letters, and gratings surrounded by bars, E letters, and gratings, respectively. A crowding effect, i.e., a worse perception of test objects surrounded by other images, was revealed. However, the perception of Landolt Cs, E letters, and gratings showed age-dependent differences. The separation between the stimulus and surrounding images at which the perception of gratings and other images worsened decreased with age increasing up to 16–17 and 12 years, respectively. The age-related differences were explained by the immaturity of selective-attention mechanisms.