Association of Circulating Extracellular Matrix Components with Central Hemodynamics and Arterial Distensibility of Peripheral Arteries.

Background: In addition to neuronal and endothelial regulators of vascular tone, the passive mechanical properties of arteries, determined by the molecular structure of extracellular matrices, are the principle modulators of vascular distensibility. Specifically, the association between collagen type IV (Col IV), a constituent of basement membrane, and arterial compliance remains unclear.

Methods: In 31 healthy adult men, radial applanation tonometry and pulse wave analysis were used to assess aortic augmentation index (AIx), aortic-to-radial pulse pressure amplification (PPAmpl), and time to reflection wave.

Cardiorespiratory Coordination in Hypercapnic Test Before and After High-Altitude Expedition.

Coordination of cardiovascular and respiratory systems enables a wide range of human adaptation and depends upon the functional state of an individual organism. Hypoxia is known to elicit changes in oxygen and carbon dioxide sensitivity, while training alters cardiorespiratory coordination (CRC). The delayed effect of high altitude (HA) acclimatization on CRC in mountaineers remains unknown.

Effect of Acute Hypoxia on Cardiorespiratory Coherence in Male Runners.

Understanding the mechanisms of oxygen supply regulation, which involves the respiratory and cardiovascular systems, during human adaptation to intense physical activity, accompanied by hypoxemia, is important for the management of a training process. The objectives of this study were to investigate the cardiorespiratory coherence (CRC) changes in the low-frequency band in response to hypoxic exposure and to verify a dependence of these changes upon sports qualification level in athletes. Twenty male runners aged 17-25 years were exposed to acute normobaric hypoxia (10% O) for 10 min.

A quantitative method for estimating the adaptedness in a physiological study.

Background: Existed mathematical models of individual adaptation are mostly reductionist by nature. Researchers usually a priori consider the subject adapted basing only on the fact of continued or prolonged influence of the harmful factor. This paper describes a method that allows assessing the physiological adaptedness to experimental challenges on the basis of holistic approach and quantitative criteria.

Associations of Del 301-303 alpha2B-adrenoceptor gene polymorphism with central hemodynamic parameters in the northern Russian population.

The ADRA2B gene 301-303 I/D polymorphism is associated with various cardiovascular phenotypes. However, an association of genotypes with the timing structure of cardiac cycle remains unclear. The central hemodynamic parameters were assessed by pulse wave analysis in 63 residents of the Kola Peninsula (68 N) aged 27-65 yr.

Seasonal inconstancy of human sex ratio at birth.

A large body of literature describes relationships between the sex ratio at birth and modifying factors. The relationships that display seasonal fluctuations are hypothesized to reflect causal impact of periconceptional and later intrauterine effects. This short review summarizes the results of studies that investigated internal and external influences on the seasonal pattern of human sex ratio at birth.

Limb muscle hemodynamics and arterial distensibility depend on atmospheric pressure in hypertensive men.

Objective: To verify whether peripheral blood circulation and arterial wall distensibility are influenced by atmospheric pressure (AtPr) and to examine if their association is dependent on age and/or sex.

Methods: Associations among natural AtPr levels (on the examination day as well as 1 and 2 days prior), limb muscle hemodynamics, and distensibility of conduit arteries were retrospectively examined in an observational study of 276 untreated patients with primary moderate hypertension (mean age 56.4 years, 194 men).

Reduced solar activity favors twin maternities.

Mechanisms underlying effects of physical factors on twin births are unclear. The present work studied an association between monthly and yearly multiple birth rates (MBRs) in the Novosibirsk region, south-west Siberia, in relation to solar activity (sunspot numbers) and geomagnetic activity (Ap index) from 1957 to 2008. The difference was verified by comparing the yearly MBR observed in 3-year peaks (M = 7.

Seasonality bias in adverse pregnancy outcomes in Siberia.

Objective: To examine which months are unfavourable for conception in the region with the severe continental climate.

Design: Retrospective population based study.

Methods: Monthly data on incidence rate for gestose, maternal anaemia, pyelonephritis, threat to spontaneous abortion, stillbirth, perinatal death and infant death at age under one year were extracted from medical records of obstetric, delivery, and paediatric hospitals in Novosibirsk (1976-1980), Norilsk (Taimir peninsula), and Mirny (western Yakutia).

Life span of people who died from cardiovascular diseases in Siberia: a comparative study of two populations.

Objectives: To assess associations between mean age at death from cardiovascular disease (myocardial infarction, acute heart failure, ischemic heart disease and stroke) and sex, education, socio-professional status, marital status, region of residence at birth, month and season of birth and of death in dependence of climatic conditions.

Design: A retrospective analysis of death certificates in two Siberian cities from 1971 to 1978 (Novosibirsk, south-western Siberia) and from 1968 to 1985 (Mirny, western Yakutia).

Methods: Analysis of variance, test for seasonality.