Brain Bioelectric Responses to Short-Term Heart Rate Variability Biofeedback Training in Indian and Russian University Students Studying in the Russian Arctic.

Heart rate variability biofeedback (HRV BF) training aids adaptation to new climatic, geographical, and social environments. Neurophysiological changes during the HRV BF in individuals from tropical regions studying in the Arctic are not well understood. The aim of this study was to research electroencephalographic (EEG) changes during a single short-term HRV BF session in Indian and Russian students studying in the Russian Arctic.

[Assessment of visual functions within the sensory domain of intrinsic capacity in older adults].

Unlabelled: Intrinsic capacity and quality of life of older adults are determined by many factors, including the functional state of the organ of vision.

Purpose: This study assessed the visual functions of elderly residents of Northern European Russia and examined the relationship between visual impairment and sociodemographic characteristics, ophthalmic conditions, and preservation of work capacity and social functions.

Material And Methods: This cross-sectional study included a random population sample of older adults (ages 60-74) from Arkhangelsk, Russia (=604).

The Association between Kidney Function Biomarkers and Delayed Memory Impairments among Older Adults in the European North of Russia.

The prevention of memory decline requires better knowledge of biological markers. We studied the associations between kidney function biomarkers and memory decline (assessed with the Mini-Mental State Examination-MMSE) in elderly individuals without dementia (MMSE 24-30, age 60-74 years, = 643, Arkhangelsk, Russia). Participants were divided by sex and into three groups according to the delayed memory performance: recall of 0-1, 2, and 3 out of 3 words.

Parameters of Auditory Evoked Related Potentials P300 in Disorders of Different Cognitive Function Domains (Visuospatial/Executive and Memory) in Elderly Hypertensive Persons.

The neurophysiological correlates of certain types of cognitive impairment in relation to the spatial pattern of auditory cognitive evoked-related potentials (ERPs) in hypertensive persons remain unclear. The aim of this study was to determine the parameters of ERPs (N200, P300) in impaired different domains (visuospatial/executive and memory) of cognitive function in arterial hypertension, including cardiovascular ischemic events. A total of 46 patients (65-84 years) were observed.

Time Estimation or Autonomic Heart Rate Regulation: Which Mechanism Is More Sensitive in the Development of Internet Addiction in Adolescents?

The aim of the study was to assess different combinations of time estimation ability and heart rate variability (HRV) parameters in adolescents during developing of Internet addiction (IA). The study included adolescents aged 16-17 ( = 49) living in the southern region of Russia. IA was measured using the Chen Internet Addiction Scale (CIAS).

Differences in the Sensitivity of the Baroreflex of Heart Rate Regulation to Local Geomagnetic Field Variations in Normotensive and Hypertensive Humans.

Synchronization between heart rate variability (HRV) in the low-frequency (LF) range (0.04-0.15 Hz) and 1-min variations in the components (X, Y, Z)and the total vector (F) of geomagnetic induction (nT) was studied in normotensive (blood pressure up to 140/90 mmHg) and hypertensive (blood pressure above 140/90 mmHg) individuals living in the Arkhangelsk region (60°51'52″ N 39°31'05″ E).

Neurophysiologic Reactions during Heart Rate Variability Biofeedback Session in Adolescents with Different Risk of Internet Addiction.

The aim of this study was to determine electroencephalogram (EEG) in a session of heart rate variability biofeedback (HRV BF) in adolescents with different Internet addiction (IA) risks. In total, 100 healthy adolescents aged 16-17 years with minimal risk of IA (Group I, 35%), pronounced risk of IA (Group II, 51%), and stable pattern of IA (Group III, 14%) using the Chen Internet Addiction Scale were examined. HRV and EEG parameters were determined at baseline (5 min), and then during the short-term HRV BF session (5 min), in order to increase the total power (TP, ms) of the HRV spectrum.

[Comparative evaluation of the EEG in adolescents with different risk of the Internet addiction living in the Northern and Southern regions].

Objective: Performing comparison of EEG in adolescents living in the Northern and Southern regions and having different risk of Internet-addiction (IA).

Material And Methods: School adolescents of 16-17 years old, permanently living in the Northern (=55) and Southern (=55) regions of the Russian Federation were examined. According to Chen's scale (CIAS) the adolescents living in both regions were divided into 3 groups: group I - with minimal risk of IA; group II - with IA inclination; group III - with formed IA.

Heart Rate Variability, Time Estimation and Internet-Dependent Behaviour in 16-17-Year-Old Adolescents: A Study in Russian Arctic.

Internet-dependent behaviour in adolescents can contribute to a change in the function of the nervous system, which is reflected in the violation of time perception and autonomic regulation of the heart rate. The aim of the study was to determine groups of individuals with different risks of Internet addiction (IA) in relation to heart rate variability (HRV) parameters and the efficiency of time estimation in adolescents aged 16-17 years living in the Russian Arctic. Adolescents aged 16-17 years ( = 49-32 females, 17 males) living in Yamalo-Nenets Autonomous Okrug (Russia) were observed.

Cardiovascular response to physical exercise and the risk of Internet addiction in 15-16-year-old adolescents.

Background And Aim: Subjective symptoms of Internet addiction (IA), such as interpersonal and health-related problems (IH-RP), do not correlate with objective physiological parameters. This study aimed to investigate the cardiovascular reactivity after physical exercise in 15-16-year-old adolescents showing different severities of symptoms of health-related problems due to Internet overuse.

Methods: This study included 20 healthy adolescents (boys, 15-16 years) with different risks of IA (by the Chen internet addiction scale [CIAS]).

[EEG spectral characteristics during heart rate variability biofeedback in healthy people].

Aim: To evaluate changes in electroencephalogram (EEG) spectral characteristics during a single session of heart rate variability biofeedback (HRV BF).

Material And Methods: One hundred and fifty adolescents, aged 16-17 years, were studied. Adolescents of the BF-group (n=110) conducted HRV BF session to enhance vagal influences on the heart rhythm.

[Individual Types Reactivity of EEG Oscillations in Effective Heart Rhythm Biofeedback Parameters in Adolescents and Young People in the North].

A single session of heart rate variability (HRV) biofeedback in apparently healthy young people and adolescents aged 14-17 years in order to increase vagal effects on heart rhythm and also electroencephalograms were carried out. Different variants of EEG spectral power during the successful HRV biofeedback session were identified. In the case of I variant of EEG activity the increase of power spectrum of alpha-, betal-, theta-components takes place in all parts of the brain.

[The dynamics of hormonal indicators in women of Arkhangelsk under stimulation of corticotropine].

The test with pharmaceutical "Synachten Depot", a synthetic analogue of corticotropine was carried out. The sampling consisted of 30 clinically healthy women aged from 20 to 30 years and residents of Arkhangelsk. The scheme of blood sampling provided basal sample, 30 and 60 minutes, I and 4 days after administration of pharmaceutical.

[Synchronization in human heart rate dynamics and Pc5 geomagnetic pulsations at different latitudes].

Eight experiments were conducted in synchronized monitoring of cardiac indices in six healthy women at rest simultaneously in three geographic locations--Sofia, Moscow and Arkhangelsk. Comparing spectra of the dynamic time series of the pulse and variations in the horizontal component of the geomagnetic field vector in the frequency range of Pc5 geomagnetic pulsations showed that the main oscillation periods represented in physiological and geophysical time series at each time moment largely coincide. This effect was observed roughly to an equal extent for volunteers who underwent the measurements in all three geographic locations.

[Comparison of electroencephalogram changes at cardiovascular training in adolescents of subpolar and polar northern territories].

The features of the electroencephalogram (EEG) at the heart rate variability single biofeedback session in adolescents aged 15-17 years living in the subpolar and polar northern regions were determined. In adolescents of the subpolar region identified shaped age EEG pattern. We have established higher diencephalic and subcortical brain structures activity manifested in the elevated theta-activity levels and the diffuse photic driving reactions in adolescents of the polar region than in adolescents of subpolar region.

[Autonomic nervous status and bioelectric brain activity in adolescents-inhabitants of the Polar north].

Background: Northern European areas are differing in degree of extreme climatic conditions in the Polar and Subpolar latitudes. Formation of the nervous system in adolescents most of all is affected by these adverse climatic factors.

Objective: The aim was to study of the autonomic regulation of cardiac activity and brain bioelectric activity in adolescents-inhabitants of the North depending on these autonomic nervous tones.

[The success of heart rate variability biofeedback parameters in persons with different levels of blood pressure].

Objective: The aim was to determine the nature of cardiovascular reactions during a single session of heart rate variability (HRV) biofeedback in order to increase vagal effects on heart rhythm in patients with different initial levels of blood pressure (BP).

Participants And Methods: 33 people with normal blood pressure (group I), 20 people with uncorrected arterial hypertension (AH) grade 1-2 (group II) and 22 people with AH grade 1-2 taking antihypertensive drugs (group III) were observed. The parameters of heart rate variability (HRV), BP and pulse aximetry in the initial stage, during a single HRV biofeedback session and after this session in order to increase the total power of the HRV spectrum (each stage 5 min).

Comparative analysis of the response of microcirculation parameters and blood pressure to geomagnetic activity in healthy people.

We analyze the results of daily laser Doppler flowmetry monitoring of blood microcirculation parameters in 9 healthy volunteers performed in 2006-2009. Dependence of microcirculation and BP parameters on geomagnetic activity was analyzed separately in each volunteer (the influence of ambient temperature was previously excluded). Significantly increased parameters of microcirculation in response to higher geomagnetic activity were found in 4 volunteers (44%) and elevated BP in 1 volunteer; in other cases, no reaction was detected.

[Thyroid effect on brain activity in adolescents during heart rhythm biofeedback session].

Types of neurophysiologic and thyroid condition in 15-17-year old adolescents were studied for the purpose of heart rhythm biofeedback session effect by heart rhythm variability parameters. Changes of heart rhythm vegetative regulation activity modulate functional capacities of central vegetative regulation structures. The biofeedback training with heart rhythm variability parameters increases brain bioelectrical activity in different frequency ranges.

[Relation between microcirculation parameters and Pc3 geomagnetic pulsations].

An individual analysis of long-term monitoring of microcirculation parameters of nine healthy volunteers showed that an increase in the geomagnetic activity led to an increase in tissue perfusion, variability of blood flow and growth of the amplitude of neurogenic and myogenic oscillations in four volunteers. It was found that the degree of microcirculation sensitivity to the level of geomagnetic activity values with time and is proportional to its average level in the period of measurement. A comparison of frequency ranges of oscillations of blood flow and variations of the geomagnetic activity shows that neurogenic and myogenic oscillations showing the highest sensitivity to the geomagnetic activity have the same frequency as geomagnetic Pc3 pulsations.

[Photo dependent changes in the endocrine system activity in teenagers from different European North latitudes].

The comprehensive study was concerned with the within year dynamics of hormonal profile in two groups of teenagers (13-16 y.o.) resident in different latitudes and climate-ecological conditions of the European North of Russia (on the border of pre-polar and medium altitude regions).

[Vegetative cardiac rhythm regulation as a function of the morning melatonin levels in teenagers-northerners on a background of mental effort].

Seventy normal 12-15 y.o. teenagers in the Arkhangelsk oblast of Russia (in latitude 61 north) were investigated in the pubertal period (June, September, December).

[The age dynamic of hormonal levels in children living in different latitudes in European North].

An investigation simultaneously of hormonal profile in children of 10-16 years living in different latitudes and climato-ecological conditions in Russian European North (in the border of polar and middle latitudes) was performed. The increased thyrotropin level was revealed in 35% of children in the south (61 degrees North) and in 32% of children in the North (64 degrees 30' North). The thyroid hormones (thyroxin, triiodothyronine) are at low normative bound.