[NUTRITIONAL STATUS IN THE EXPERIMENT WITH 105-DAY ISOLATION AS THE FIRST PHASE OF PROJECT MARS-500].

In a 105-day experiment simulating crew life in a space exploration vehicle, shifts in the nutritional status were assessed in 6 test subjects differing in the body mass index, basal metabolism, attitude to the diet, physical exercise and workload. Results of the investigation showed that because of the hard physical work the nutritional status of test subjects was described by more intensive basal metabolism, elevated metabolism of carbohydrates and lipids, and their increased mobilization from depots. Food ration, though it was sufficient to sustain health and fairly high performance, failed to meet fully individual taste preferences and energy needs for physical activities. The heavy workloads required mobilization of lipids from adipose depots, and a decrease of the hepatic detoxification and metabolic capacities. Self-limitation of eating protein-rich desserts led to a relative deficiency of protein intake. These faults of the diet were the reason why 4 out of 6 test subjects reduced their basal metabolism and lost body mass. Recovery of metabolism and slowdown of the body mass loss were achieved by supplementing meals with available protein-containing products.

[Electron microscopy and hystology of the third ventricle ependyma of rat's brain after repeated simulation of the effects of microgravity].

Scanning electron and light microscopy were applied to study the third ventricle ependyma in rat's brain after 30-d tail-suspension, 30-d readaptation to the horizontal position, and repeated 14-d suspension in parallel with another group of rats exposed to a single 14-d suspension. Despite the repeated blood redistribution toward the head, the second tail-suspension produced significantly less grave destruction of the ependymal cell structure and cilia ultrastructure than the single 14-d or previous 30-d one, which suggests that simulation of microgravity repeated after substantial delay imparts much more persistence to the cerebrospinal fluid outflow from the brain ventricles into the saggital sinus.

Ultrastructure of ependyma in brain third ventricle of the rats exposed to repeated tail-suspension. Scanning electron microscopical study.

By means of scanning electron microscopy the ultrastructure of ependyma was studied in the brain third ventricle of the rats repeatedly exposed to 14-day tail-suspension (TS). Animals were subjected to TS for 30 days, then readapted to horizontal position during 30 days and again, repeatedly subjected to TS for 14 days simultaneously with the rats which were in TS for the first time during 14 days. Repeated TS of rats, inspite of repeated redistribution of body liquid mediums in cranial direction, results in considerably less expressed destructive changes in ultrastructure of ependymocyte cilia, then after primary 14- and 30-day TS, showing much greater cerebrospinal fluid (CSF) outflow from brain ventricles into sagittal venous sinus at postponed for a long time, repeated simulation of weightlessness effects in comparison with CSF outflow at primery one.

[Population genetic study of Russian cosmonauts and test subjects: genetic demographic parameters and immunogenetic markers].

Genetic demographic characteristics and immunogenetic markers (blood groups ABO, Rhesus, MNSs, P, Duffy, Kidd, and Kell) have been studied in a group of 132 Russian cosmonauts and test subjects (CTSG). Analysis of pedigrees has shown a high exogamy in the preceding generations: almost half of the subjects have mixed ethnic background. According to the results of genetic demographic analysis, a sample from the Moscow population was used as control group (CG). Comparison between the CTSG and CG has demonstrated significant differences in genotype frequencies for several blood group systems. The CTSG is characterized by a decreased proportion of rare interlocus genotypic combinations and an increased man heterozygosity. Analysis of the distributions of individual heterozygosity for loci with codominant expression of alleles has shown that highly heterozygous loci are more frequent in the CTSG. Taking into account that the CTSG has been thoroughly selected from the general population, it is concluded that heterozygosity is related to successful adaptation to a space flight.

[Growth of three-dimensional complexes of living cells in the process of rotational cultivation]. / Vyrashchivanie trekhmernykh kompleksov zhivotnykh kletok v usloviiakh rotatsionnogo kul'tivirovaniia.

Unlike the monolayer cultures, three-dimensional (multilayer) cultures of living cells make it possible to more closely imitate events occurring in native tissues. Rotating cultivators for three-dimensional cultures create analogous conditions of reduced gravity and, therefore, can be used in ground-based investigations of the biological effects of space flight. We have designed a disposable cultivation cell with diffused gas exchange and a device to rotate the cell at a controlled speed about the horizontal axis. Immortalized CH-fibroblasts were attached to a glass carrier pretreated with polylysine. Cultivation was performed for 2-3 days at 8 rot./min. A rapid growth of three-dimensional cell complexes was observed during the cultivation. The investigation demonstrated that multilayer cultures of immortalized CH-fibroblasts represent a convenient model for studies in cell biology and development of technologies of growing d-dimensional living cell complexes as a source of implants from autologic cells (including stem cells) thus resolving the problem of donator materials.

Three-dimensional (3-D) structures formed by immortalized human fibroblast cells in simulated microgravity.

3-D structures were obtained at rotatory cultivation of CH immortalyzed human fibroblasts attached to glass microcarrier beads. The morphology of cells from these cultures was studied by scanning electron microscopy. A number of structural alterations in fibrillar filopodia of CH cells were revealed as compared with cells grown in stationary monolayer cultures, namely, smaller length, uneven caliber, the presence of curvatures, and disturbed branching pattern. Filopodia displayed unusual formations: protuberance-like and "mammoth's tusk"-like off-shoots, foamy spreadings in distal segments, and spiral windings of filopodia. The susceptibility of CH cells morphology to mechanical environment makes them a promising model for gravitational biology studies.

[The effect of weightlessness on erythrocyte resistance in vivo and in vitro]. / Vliianie nevesomosti na rezistentnost' éritrotsitov in vivo i in vitro.

One of the significant changes developing in animals and humans in the space mission environments is a decreased volume of red blood mass. For the analysis of causes of this phenomenon it is reasonable to compare the data on erythrocyte resistance to hemolysis in vivo and in vitro obtained in the rat experiments on Cosmos biosatellites. After 18 to 22-day space missions, the osmotic resistance of erythrocytes in vitro in animal blood samples and the level of spontaneous hemolysis in vivo directly in the vascular bed of rat have been determined. To this end, an original method based on a quantitative determination of 14Co in the expired air following previous (prior to space mission) 2(14)C glycine labeling in vivo of erythrocyte 2 group has been utilized. In both cases there were a decreased erythrocyte resistance and an increased hemolysis level. During the studies in vivo these changes were significantly great. Inflight application of artificial gravity of 1 G prevented microgravity-induced changes in the characteristics of the erythrocyte life cycle. The changes in erythrocyte shape and membrane properties as well as the factors affecting the cells in vascular bed (altered concentration of fatty acids in blood plasma and others) are discussed as possible causes of the above alterations.

[Significance of the deviation of the forced expiratory spirogram from the exponential relation]. / Znachenie otklonenii spirogrammy forsirovannogo vykhoda ot eksponentsial'noi zavisimosti.

The forced expiratory curve was divided into individual parts which presented its exponential dependencies. The tau-parameter depicting the speed of exponential process was determined for each part. Variations of this parameter during the course of forced expiration reflected obstructive changes in the bronchopulmonary system of man. The method is highly sensitive to the small airway pathology. It enables the determination of the site of the action of a broncholytic and the differentiation between the obstruction of small and large airways. Moreover, it makes it possible to establish whether the expiratory speed improvement is the result of airways obstruction release or the lung restriction release.

[Determination of the alveolar dead space]. / Opredelenie al'veoliarnogo mertvogo prostranstva.

The author suggests a method of finding the alveolar dead space (AIDS), i.e. the part of the functional dead space (FDS) which presents the greatest difficulties for determination. A1DS determination is based on the difference in the CO2 concentration in the venous blood flowing to the lungs for oxygenation under conditions of respiration at rest, and of CO2 concentration in the alveolar portions of expriation following 10-sex breath withholding at the level of the usual inspiration. The mean A1DS volume (VDA1) in % to the alveolar part of the tidal volume for 20 healthy persons in sitting position and in 12 of them in lying position was found: VDA1 (in sitting position)= = 8.0 +/- 1.5% (P = 0.95), sigma = 3%; VDA1 (in lying position) = = 5.0 +/- 0.7% (P = 0.95), sigma = 2.6%. It is suggested that FDS determined by this method be used to judge the efficacy of using the inspired air in the lung ventilation, to determine AIDS in the diagnosis of lung embolism, to judge the pulmonary circulation shunt by the difference between the value found according to Bohr's formula for FDS and the FDS value established according to the suggested formula.

[Determination of the inequality of ventilation by the helium mixing time in a spirograph--lung system]. / Opredelenie neravnomernosti ventiliatsii po vremeni smesheniia geliia v sisteme legkie--spirograf.

The dependence of the time of He mixing in the lung-spyrograph system upon the factors influencing its value was taken into consideration. Cases of equal lung ventilation of the lungs were graphically illustrated; the "ideal" mixing time was determined with the aid of these diagrams. It is suggested that the inequality of the lung ventilation can be judged by the value by which the mixing time obtained in the examination of the patient's respiration exceeded the "ideal" one found by the diagram in the same patient.