PubMed Health⌕ Search

Biomedical subjects

A O Lazarev

Publications and source records attributed to A O Lazarev.

12 recordsLinked to original sources

Physiological reactions of primates to 9-D immersion and head-down tilt.

Purpose of the investigation was to compare physiological reactions of primates (Macaca mulatta) to microgravity simulated by immersion and head-down tilt (HDT). In immersion experiments, primates in waterproof suits were put into motion-restraining chairs and immersed into water (t=35.4 degrees C) breast-deep for 9 days. In 9-d HDT experiments, prone primates were motor restrained in dedicated tilt beds at -5 degrees. It was found that the CNS functioning was significantly affected, the plasma volume reduced and the marrow erythropoietic function declined. Atrophy developed in leg muscles on a backdrop of iliopectineal spongy osteopenia. Loss in hydration, inhibition of erythropoietic hemopoiesis and iliopectineal spongy osteopenia were more pronounced following immersion than HDT.

Adaptation, Physiological↗

[Measurement of the human skin electrical potentials in the tibial projection region].

Skin electrical potentials (EP) were measured in the region of the medial tibia projection in human subjects in the ordinary state and after 4 days of bed rest. The intent was to determine if there is an interaction of the slow electrical activity of visceral organs and tissues with the electrical activity of the basal epithelium which, according to the author's hypothesis, controls some of the mammalian body functions. EP values were found to depend on positioning of electrodes relative to the bone proximal epiphysis. This dependence yielded a non-linear curve. Individual EP curves were relatively stable. Evidence was obtained that 4-d bed rest caused a significant decline in the electrical activity in the region of the skin tibia projection.

Adult↗

[Noncontact system of bugs motor activity recoding].

A noncontact system for recording the motor activity of beetles is based on utilisation of infrared radiation. The system and digital PC input-output card DIO-96 were integrated into a 96-channel computerized facility to maintain, monitor and perform circadian studies of insects which was experimentally tested.

Animals↗

[Electroepidermic activity].

Amplitude-time parameters of spontaneous fluctuations of the electroepidermic activity (EDA) were studied in human subjects during relative rest. Spontaneous EDA was shown to be markedly individual by character. No correlation was stated between the amplitude, period of spontaneous fluctuations, and baseline EDA. The amplitude variation range can reach 171% and the fluctuation duration range makes 85% of the mean value. The role and origin of spontaneous EDA fluctuations are discussed.

Action Potentials↗

[The effect of UV-radiation on the sensory and nociceptive sensitivity of the skin of hairless mice].

The effect of UV-radiation of 12.17 and 3.27 W/m2 (with the dose rate = 23.19 kJ/m2) on the sensory and nociceptive sensitivity of the skin of nude mice was investigated in two experimental series. It was found that the pattern of changes in the sensory and nociceptive sensitivity of the skin were not correlated with UV-radiation intensity, the dose rate being the same. However, the changes were more significant, manifested earlier and disappeared later during irradiation with UV-rays of 12.17 W/m2 than with UV-rays of 3.27 W/m2.

Animals↗

[Differences in electrical potentials of different areas of human skin as a characteristic of the functional state of the body].

Constant electric field (CEF) of an organism in various physiological states has been studied by two complementing methods. The states "healthy" and "sick" are described in terms of electrical potential difference (EPD) between two skin regions of man. It is shown that at the state "sick" equipotentiality of CEF is disturbed in the plane perpendicular to the principal axis of the body symmetry. It enables to outline further development of differential diagnistics of this state.

Diagnosis, Differential↗

[The constant electrical potentials of the skin as an integral index of the functional state].

The electric potential difference between the head and hind limb of monkeys was studied before, during and after 2h-restraint in a supine position. The kinetics of electric potentials depended on the initial electric polarity of animals. The role and place of the basal system of epithelium (basal membrane and basal cell layer) in functioning of multicellular organisms is discussed.

Animals↗

[The use of human skin reflectance spectra for the quantitative assessment of individual sensitivity to ultraviolet radiation].

Reflection spectra of human skin of various ethnic types in the range of 370-790 nm were measured and analyzed. Correlation between reflection coefficients and minimal erythemal doses was estimated. The formula has been devised which is suitable for defining minimal erythemal doses both for open and closed parts of the body irrespective of pre-exposition to sun radiation.

Buttocks↗