Decrease of coherence between the respiration and parasympathetic control of the heart rate with aging.

The study of coordinated behavior between different systems of the human body provides useful information on the functioning of the body. The peculiarities of interaction and coordinated dynamics of the heart rate and respiration are of particular interest. We investigated the coherence of the processes of respiration and autonomic control of the heart rate for people of different ages in the awake state, in sleep with rapid eye movement, and in deep sleep. Our analysis revealed a monotonic decrease in the coherence of these processes with increasing age. This can be explained by age-related changes in the system of autonomic control of circulation. For all age groups, we found a qualitatively similar dynamics of the coherence between the studied processes during a transition from the awake state to sleep.

Synchronization of infra-slow oscillations of brain potentials with respiration.

We study the synchronization of infra-slow oscillations in human scalp electroencephalogram signal with the respiratory signal. For the cases of paced respiration with a fixed frequency and linearly increasing frequency, we reveal the phase and frequency locking of infra-slow oscillations of brain potentials by respiration. It is shown that for different brain areas, the infra-slow oscillations and respiration can exhibit synchronous regimes of different orders.

[Paraoxonase: The Universal Factor of Antioxidant Defense in Human Body].

The paraoxonase (PON) gene family includes three members: PON1, PON2, and PON3 aligned in tandem on chromosome 7 in humans. All PON proteins share considerable structural homology and have the capacity to protect cells from oxidative stress; therefore, they have been implicated in the pathogenesis of several inflammatory diseases, particularly atherosclerosis. Increased production of reactive oxygen species as a result of decreased activities of mitochondrial electron transport chain complexes plays a role in the development of many inflammatory diseases, including atherosclerosis. PON1 and PON3 proteins can be detected in plasma and reside in the high-density lipoprotein fraction and protect against oxidative stress by hydrolyzing certain oxidized lipids in lipoproteins, macrophages, and atherosclerotic lesions. Paraoxonase 2 (PON2) possesses antiatherogenic properties and is associated with lower ROS levels. PON2 is involved in the antioxidative and anti-inflammatory response in intestinal epithelial cells. In contrast to PON1 and PON3, PON2 is cell-associated and is not found in plasma. It is widely expressed in a variety of tissues, including the kidney, and protects against cellular oxidative stress. Overexpression of PON2 reduces oxidative status, prevents apoptosis in vascular endothelial cells, and inhibits cell-mediated low density lipoprotein oxidation. PON2 also inhibits the development of atherosclerosis, via mechanisms involving the reduction of oxidative stress. In this review we explore the physiological roles of PON in disease development and modulation of PONs by infective (bacterial, viral) agents.

[Phase and frequency locking of 0.1 Hz oscillations in heart rhythm and baroreflex control of arterial pressure by respiration with linearly varying frequency in healthy subjects].

We studied the features of functional interaction between the subsystems of autonomic control of heart rate (HR) and arterial pressure (AP) giving rise to 0.1 Hz oscillations in R-R intervals (RRI) and photoplethysmogram (PPG). The study included 25 healthy subjects (6 women and 19 men) aged between 18 and 32 years. The signals of RRI, PPG and respiration were simultaneously recorded under breathing with a frequency linearly increasing from 0.05 Hz to 0.25 Hz within 25 minutes in a sitting position of a subject. The possibility of phase and frequency locking of 0.1 Hz oscillations in RRI and PPG by respiration is shown. We revealed that theses oscillations have different width and location of the intervals of phase and frequency locking by respiration. This distinction points to the functional independence between the mechanisms of autonomic control of 0.1 Hz oscillations in RRI and PPG.

EEG biomarkers of activation of the lymphatic drainage system of the brain during sleep and opening of the blood-brain barrier.

The lymphatic drainage system of the brain (LDSB) is the removal of metabolites and wastes from its tissues. A dysfunction of LDSB is an important sign of aging, brain oncology, the Alzheimer's and Parkinson's diseases. The development of new strategies for diagnosis of LDSB injuries can improve prevention of age-related cerebral amyloid angiopathy, neurodegenerative and cerebrovascular diseases. There are two conditions, such as deep sleep and opening of the blood-brain-barrier (OBBB) associated with the LDSB activation. A promising candidate for measurement of LDSB could be electroencephalography (EEG). In this pilot study on rats, we tested the hypothesis, whether deep sleep and OBBB can be an informative platform for an effective extracting of information about the LDSB functions. Using the nonlinear analysis of EEG dynamics and machine learning technology, we discovered that the LDSB activation during OBBB and sleep is associated with similar changes in the EEG θ-activity. The OBBB causes the higher LDSB activation vs. sleep that is accompanied by specific changes in the low frequency EEG activity extracted by the power spectra analysis of the EEG dynamics combined with the coherence function. Thus, our findings demonstrate a link between neural activity associated with the LDSB activation during sleep and OBBB that is an important informative platform for extraction of the EEG-biomarkers of the LDSB activity. These results open new perspectives for the development of technology for the LDSB diagnostics that would open a novel era in the prognosis of brain diseases caused by the LDSB disorders, including OBBB.

Vascular endothelial growth factor and its receptors in the placenta of pregnant women with obesity.

Comparative morphological study of placentas from women with obesity and normal body weight was performed. Expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR-1, VEGFR-2, VEGFR-3) was detected by immunohistochemical methods. Nonbranching angiogenesis predominated in the placentas from obese women. Immunohistochemical analysis showed reduced intensity of the reaction to VEGF in the syncytiotrophoblast and vascular endothelium of stem villi and enhanced VEGF expression in non-villous cytotrophoblast and endothelial cells of capillaries of mature intermediate and terminal villi; reduced expression of VEGFR-1 and increased levels of VEGFR-2 and VEGFR-3 in the studied structures were also noted.

[Immunohistochemical evaluation of the distribution of vascular endothelial growth factor in the placenta, placental bed in normal pregnancy and in women with preeclampsia].

VEGF expression was immunohistochemically studied in 35 placental fragments and 15 placental bed biopsy specimens in a control group and in 34 placental fragments and 16 biopsy specimens in women with preeclampsia. The female serum concentrations of VEGF and sFlt-I were measured in both groups. There was a drastic reduction in VEGF expression in the placenta (syncytiotrophoblast, free symplasts, syncytial kidneys); the placental bed biopsy specimens showed the impaired rearrangement of maternal-placental arteries with the lower VEGF expression in the cytotrophoblastic cells from women with preeclampsia. The blood displayed a 10-fold reduction in VEGF along with a 3.5-fold increase in SFlt-1 concentrations. Deficiency of free (circulating) VEGF-A that is so essential for normal endothelial function is likely to cause its structural changes that are united under the term "endotheliosis" as one of the leading mechanisms of the pathogenesis of gestosis.

[The role of immune placental inflammation in the genesis of complicated pregnancy].

Immune inflammation is a typical pathophysiological process caused by exogenous and endogenous factors. Fibrinoid necrosis and cell infiltrations are the morphological features of tissue lesion caused by immune inflammation. Tissue lesion in immune inflammation may be connected with immune complex (IC) formation or T-cell aggression. Lesion caused by antigen-antibody complexes develops as a result of direct IC formation in the tissue or their inflow from microcirculation. Potential sources of IC in the placenta are maternal blood flow, the formation of IC between maternal antibodies (AB) and embryonic antigens, and IC formation in fetal blood vessels. After sedimentation in the placenta, circulating IC can cross syncytiotrophoblast tissue with the participation of specific receptors to immunoglobulin Fc-fragment. The process of antifetal AB formation may start in the maternal organism, as a result of which it forms AB to embryonic and placental antigens, including paternal Rh, ABO, and HLA, and some trophoblast antigens. IC are able to initiate inflammatory process through interaction with the compliment system, through the activation of macrophages excreting cytokines (TNF-alpha and IL-1), and through influencing basophiles and thrombocytes (the liberation of vasoactive amines). Gestosis is associated with system inflammatory response with endothelial dysfunction as the main element. As the clinical features of gestosis do not develop before 20 weeks of pregnancy, its clinical manifestation is preceded by increased fetal blood-brain barrier permeability, elevation of the level of neurospecific proteins of fetal origin in maternal circulation, and the formation of specific IC causing acute endotheliosis.

A comprehensive assessment of cardiovascular autonomic control using photoplethysmograms recorded from the earlobe and fingers.

We compare the spectral indices of photoplethysmogram variability (PPGV) estimated using photoplethysmograms recorded from the earlobe and the middle fingers of the right and left hand and analyze their correlation with similar indices of heart rate variability (HRV) in 30 healthy subjects (26 men) aged 27 (25, 29) years (median with inter-quartile ranges) at rest and under the head-up tilt test. The following spectral indices of PPGV and HRV were compared: mean heart rate (HR), total spectral power (TP), high-frequency (HF) and low-frequency (LF) ranges of TP in percents (HF% and LF%), LF/HF ratio, and spectral coherence. We assess also the index S of synchronization between the LF oscillations in HRV and PPGV. The constancy of blood pressure (BP) and moderate increase of HR under the tilt test indicate the presence of fast processes of cardiovascular adaptation with the increase of the sympathetic activity in studied healthy subjects. The impact of respiration on the PPGV spectrum (accessed by HF%) is less than on the HRV spectrum. It is shown that the proportion of sympathetic vascular activity (accessed by LF%) is constant in the PPGV of three analyzed PPGs during the tilt test. The PPGV for the ear PPG was less vulnerable to breathing influence accessed by HF% (independently from body position) than for PPGs from fingers. We reveal the increase of index S under the tilt test indicating the activation of interaction between the heart and distal vessels. The PPGV spectra for finger PPGs from different hands are highly coherent, but differ substantially from the PPGV spectrum for the ear PPG. We conclude that joint analysis of frequency components of PPGV (for the earlobe and finger PPGs of both hands) and HRV and assessment of their synchronization provide additional information about cardiovascular autonomic control.

[Factors and conditions affecting the process of infecting the fetus during different pregnancy stages]. / Faktory i usloviia, vliiaiushchie na protsess infitsirovaniia ploda na raznykh srokakh beremennosti.

Etiology, pathogenesis of intrauterine infection of the fetus, factors promoting such infection and the status of the local immune system are elucidated in the paper. A changed reactivity of the immune homeostasis of a pregnant woman with a chronic infection was shown to be potentially an important factor of pathogenesis of defects in her baby. The local immunity factors of the reproductive tract, i.e. the vagina and neck of uterus, are in the forefront of anti-infectious protection, which signal an alert or limit the microorganisms' reproduction; besides, they prevent the microorganisms from penetrating into the upper genitals. The therapeutic-and-preventive schemes applicable to infected women must comprise measures targeted at eliminating an infectious agent and at normalizing the pathological changes in the performance of the immune system activity.