[EFFECT OF VOLUNTARY BREATH-HOLDING AND COGNITIVE LOADS ON REGIONAL CEREBRAL BLOOD FLOW AND BIOELECTRIC ACTIVITY OF THE BRAIN].

Cerebral blood flow and bioelectric activity were studied in 10 normal volunteers in order to assess cerebrovascular reactivity during different types of functional testing. The transcranial Doppler was used to measure linear blood velocity (LBV) in the middle cerebral artery (MCA) during maximal voluntary breath-holding (apnea), controlled verbal association test and tactile memory test. Simultaneous electroencephalography (EEG) registered the bioelectric activity of the brain cortex. Both investigations were performed continuously in the course of each test. Breath-holding induced a smooth symmetric increase of CMA blood velocity; LBV rose to maximum values in the majority of the volunteered subjects. Two subjects with small focal changes in the brain's white matter displayed an asymmetric blood flow reaction to apnea. Gain in LBV was materially less during the cognitive tests; the verbal test decreased LBV in one half of the subjects and increased LBV in the other. The tactile memory test increased LBV which was particularly high in the left CMA of all subjects. LBV dynamics during the cognitive tests was essentially different from what was observed in apnea. Blood flow variations in the course of equally the verbal and tactile tests had a regular undulatory character. Concurrent LBV and EEG monitoring made it possible to compare and contrast dynamics of the cerebral blood velocity and bioelectric activity directly during testing and thus to reveal peculiar reactions of the cerebral blood flow to cognitive and physiological testing.

[Effects of the 520-day isolation on the functional state of the cardiovascular system].

Purpose of the work was to study the cardiovascular effects of simulated factors in a 520-day crewed mission to Mars, and to validate the diagnostic value of the ultrasonic investigation of microcirculation and endothelium-dependent dilation of the right brachial artery in 6 male volunteers at the age of 28 to 39 years. It appears that 520-d isolation affected intracardiac hemodynamics and endothelium function more dramatically compared with 105-d isolation, increasing the risk of atherosclerosis. These findings add insight into the "cost of human adaptation" to very long isolation.

[Prediction of cardiac function deviations (ECG data) in the course of permanent cosmonaut's monitoring starting from selection till return to earth after short-duration space flight].

Analyzed were deviations in cardiac function in 29 cosmonauts with previous aviation and other occupations ranging of 29 to 61 y.o. who made 8- to 30-day space flights (totai number of flights = 34) between 1982 and 2006. The deviations were identified in ECG records collected during clinical selection, clinical physiological examination (CPE) before flight, insertion and deorbit in transport vehicles, and post-flight CPE. Based on the analysis, the cosmonauts were distributed into three groups. The first group (55.2% of the cosmonauts) did not exhibit noticeable shifts and unfavorable trends in ECG at any time of the period of observation. The second group (34.5%) showed some deviations during selection and pre-flight CPE that became more apparent in the period of deorbit and were still present in post-flight ECG records. The third group (10.3%) displayed health-threatening deviations in cardiac function during deorbit. These findings give start to important investigations with the purpose to define permissible medical risks and ensuing establishment and perfection of medical criteria for candidates to cosmonauts with certain health problems.

[Distribution of HLA antigens in ischemic heart disease patients with stenocardia]. / Raspredelenie antigenov sistemy HLA u bol'nykh ishemicheskoi bolezn'iu serdtsa so stenokardiei.

HLA antigens were typed by A, B, and C loci in 162 male residents of Moscow with coronary heart disease (CHD) and angina pectoris, aged 27 to 69 years. Coronary patients showed significantly increased incidence of HLA antigens B13, B15, B17, B22 and Cw3, as compared to control population samples. The rates of some histocompatibility antigens carriage were different in different patients, showing a dependence on the duration of disease, the hyperlipoproteinemic type, serum apoprotein level and some clinical characteristics (the severity of CHD, the number of affected coronary arteries).