[TESTING THE PROTECTIVE PROPERTIES OF ARGON DURING SUBACUTE EXPOSURE TO HYPOXIC HYPOXIA].

Previously it has been shown that argon has a stimulating effect on biological processes including, specifically, strong protective properties during exposure to acute (1-4 hrs.) hypoxic hypoxia. Experiments with animals under hypoxia gradually growing over 3 to 7 days may give insight into mechanisms of the argon protective action. Purpose of the work was to explore character and severity of developing disorders, to attempt their prognosis and to test potentiality of argon as a protector from the effects of subacute hypoxic exposure. In two series of experiments Wistar male rats were housed in pressure chambers with different rates of O2 reduction without argon and with argon in concentration of 32-38%. Oxygen reduction from 20.9 to 9.0% in 3 days led to the death of 50% animals. Oxygen reduction to 12.0% in 7 days and one day in low-oxygen atmosphere was harmless for animals. Argon in air makes the response to hypoxia almost twice as sharp on virtually every level (red blood system, physiological, morphological and biochemical shifts) validating the concept that argon acts as a stimulator. In context of the most critical processes of adaptation to hypoxia--activation of blood formation and lipid metabolism--this sharpening of the response results in depletion of body resources and instigates irreversible shifts.

[Experimental studies with mice on the program of the biosatellite BION-M1 mission].

Purpose of the BION-M1 project was laying the evidence and technological basis for addressing the medical issues of future remote space exploration missions by humans. The program of researches with the use of mice was focused on elicitation of cellular and molecular mechanisms of the muscular, cardiovascular and immune reactions to extended exposure in microgravity. The comprehensive studies combined lifetime measurements with investigations of mice tissues and cells by dint of the cutting-edge morphological, biochemical and molecular biology techniques. Males of mice C57/BL6 aged 4 to 5 months were chosen as the object of studies. They were distributed into the flight, ground control and two vivarium (laboratory control) groups and investigated immediately on return and after 7 days of readaptation. Some of the physiological functions were recorded throughout the flight. To ensure wellbeing of the animals in the experiments and to enhance data quality, prior to launch the mice were specially trained so as to accommodate to the group living, eating space food, and in-flight stress factors. Those of the mice that were designated for lifetime investigations were tested and received training pre-launch.

[Comparative evaluation of the effects of hypoxic gaseous mixtures varying in oxygen concentration on Japanese quail embryogenesis].

The paper presents the results of comparative characterization of the effects of low oxygen levels (10 ± 0.5 and 14.5 ± 0.5%) on developing organism. Four-day old embryos of the Japanese quail (Coturnix coturnix japonica) were chosen for the object of investigation as this is the age when avians acquire their organs and systems. Acute hypoxia (10 ± 0.5% oxygen) caused a general death of the embryos, and serious abnormalities of the eye and brain, and ectopy. Embryos that developed in the low-oxygen atmosphere (14.5 ± 0.5%) did not exhibit many of these morphological abnormalities and yet their growth was retarded apparently. Such abnormalities in acute hypoxia are ascribed to disturbance in development of extra-embryonic membranes, amnion in particular, desynchronization of morphogenetic processes and movement of embryo's tissue layers.

[Microbial fuel cells as an alternative power supply].

Purpose of the work was designing and prototyping of microbial fuel cells (MFC) and comparative evaluation of the electrogenic activity of wastewater autochthonous microorganisms as well as bacterial monocultures. Objects were model electrogenic strain Shewanella oneidensis MR-1, and an Ochrobactrum sp. strain isolated from the active anode biofilm of MFC composed as an electricity generating system. The study employed the methods typically used for aerobic and anaerobic strains, current measurement, identification of new electrogenic strains in microbial association of wastewater sludge and species definition by rRNA 16-S. As a result, two MFCs prototypes were tried out. Besides, it was shown that electrogenic activity of S. oneidensis MR-1 and Ochrobactrum sp. monocultures is similar but differs from that of the microbial association of the anode biofilm.

[Gerbil experiment in the flight of spacecraft "Foton-M3"].

The 12-d mission of Russian spacecraft Foton-M3 in September of 2007 was used as an opportunity to fly an experiment with 12 male gerbils (Meriones unguiculatus) at the age of 4-4.5 mos. and mean body weight of 51.6 grams. Considering the behavior pattern of these animals, selection and preparation of the experimental groups continued in the course of 2.5-3 months. The flight animals were contained in module Kontur-L outfitted with a self-sustained system of life support. In orbit, the animals received a palletized hydrogenous feed. The physiological and hygienic parameters of the gerbil environment during the flight complied with the official standards. Analysis of the video recorded behavior of animals in microgravity showed that virtually throughout the flight they moved chaotically along the cage never attempting to stabilize position catching at the wire netting of the cage. The animals were decapitated in 21-24 hours after landing. The investigations showed that structural and functional changes in gerbil organs and tissues were generally of the same type as in rats following fights of comparable duration. However, some differences between the animals were attributed to the specifics of water turnover in gerbils.

[Handling and maintenance of gerbils during the spacecraft Foton-M3 mission].

Pressurized low-sized module Kontur with an independent life support system (LSS) was developed by the Institute of Biomedical Problems cooperatively with the Special Design Bureau of Experimental Equipment to house gerbils (Meriones unguiculatus) aboard robotic technology-purpose spacecraft. Design of the module precludes pollution of the environment The fully equipped module weighs 69 kg; average daily power consumption is 62 watts. The environmental parameters for 12 animals flown on Foton-M3 in the period of September 14-26, 2007 were controlled within the following ranges: pO2 - 143-156 mm Hg, (mean 150 mm Hg), pCO2 - 0.76 mm Hg maximum (mean 0.64 mm Hg), temperature - 23-28 degrees C (mean 26.7 degrees C), relative humidity - 29% and 57% at the beginning and end of the flight, respectively (mean 39%). The animals consumed the palletized food prepared of natural products with a moisture content of approx. 20%. The day-night periods were 12 hrs. long. The daytime video recording of the animals went on continuously in the throughout the flight. The experiment showed that the module meets the requirements of experiments with mammals aboard returnable robotic spacecraft and piloted space stations. At the moment, the model is being redesigned for a 30-day BION-M1 mission.

[Development of chow for Mongolian gerbils suitable for the conditions of space flight].

One of formidable issues of experiments with animals in space flight is water supply. For Mongolian gerbils (Meriones unguiculatus), classed as cricetid rodents, water in chow is enough. These animals are a new object for space biology. Our purpose was to compose a full-value formula and design a chow making and long-term storage technology to provide Mongolian gerbils for in microgravity. The chow is required to have a 28-d shelf life. To assess the chow suitability on autonomous space fight, the gerbils we house in a cage with the geometry reproducing the current design of the future space animal module. The assessment was performed with adult male gerbils weighing 50.5 +/- 3.4 g on the average. The animals ate up 40.1 +/- 3.9%, i.e. less than 50% of the feed all through the period of experiment. However, by the end of the experiment the body mass and exterior remained essentially unchanged In was concluded that the chow formula can be prescribed to Mongolian gerbils housed in self-contained modules.

[Effects of short-term oxygen breathing on the human respiratory system].

Compared were effects of cryogenic and adsorptive oxygen on the respiration system in an experiment with 8 normal female volunteers. Mechanic impedance of the respiratory tract, pulmonary ventilation function, CO transport coefficient and physical performance were determined before and after 20 minutes of oxygen breathing. Breathing two types of oxygen was found to have different effects on the real part of mechanic impedance and the ventilatory function of the lung.

[Physiologically active argon-based gas mixtures as a means of creating fire-safe gaseous environments in pressurized modules of varying purpose].

Development of acute hypoxic hypoxia in consequence of fire in various pressurized modules was studied. The investigation was aimed to look into the effects of inert argon and dramatic oxygen reduction in gaseous environment on animals (Wistar rats, mice c57bl/6, balb/c and f1cbaxbalb/c hybrids, Japanese quail embryos) and microorganism (Escherichia coli strains k-12 jf 238 and k-12 jm 83). Also, inflammability of some widely used materials was assessed in order to provide inputs to developers of fire-safe gaseous mixtures for pressurized habitats. It was shown that argon is favorable to survivability of animals and to maintenance of a high level of oxygen consumption. Gaseous mixtures with oxygen content less than 15 volume % suppressed burning of selected materials. Results of the investigation offer possibilities for designing new hypoxic fire-safe gas mixtures that will provide adequate human performance and ensure survival in extreme situations.

[Effect of hypoxic argon-containing gas mixtures on developing organism].

Experimental data on the impact of argon-containing hypoxic breathing mixtures on the early embryonic growth of Japanese quail (Coturnix coturnix japonica dom.) are presented. The results showed that after 4-day incubation of eggs in an oxygen-nitrogen breathing mixture (13.8-15.0% O2, 86.2-85.0% N2) only 16.7% embryos reached the stage of 3.5-d development. Introduction in the hypoxic mixture of argon (55% of the total volume) increased the number of embryos on the stage of 3.5-4 day of normal morphological development to 60%. It became evident from the analysis that embryos developed in the O2-Ar-N2 hypoxic mixture had 25% less pathologies as compared with embryos developed in a largely nitrogen-containing gas mixture. Hence, we received the experimental evidence that 55% of argon in a hypoxic breathing mixture with up to 15% of oxygen is favorable to the early embryonic growth of Japanese quail stimulating metabolic processes in germ organism.

[Impact of hypoxic gas mixtures on embryogenesis of the Japanese quail].

Avian embryogenesis is of great interest to investigators, as the germ developing outside mother's body, is capable to react briskly to any alteration in the outer world. The paper present experimental evidence of the impact of oxygen with physical and chemical properties modified by short-cycle no-heating adsorption (SNA) in a hypoxic gas mixture (10% O2) on the early embryogenesis of the Japanese quail. Low concentrations of oxygen are known to be a dramatically disturbing factor for embryo's morphology. It was demonstrated experimentally that four days before incubation bird are highly sensitive to oxygen deficiency which is responsible for developmental abnormalities. The use of SNA oxygen reduced the frequency of pathologies in the Japanese quail germs as compared with their controls incubated in gas environment containing medical oxygen generated by low-temperature rectification.

[Effects of medium with elevated partial pressure of argon and nitrogen on morphology of Escherichia coli colonies].

The purpose was to study morphological specifics of microbial colonies cultivated in argon-containing gas medium. Investigated were computerized images of the colonies of museum strains Escherichia coil K-12. It was found that combination of elevated argon pressure (1 ata) and nitrogen pressure (1.8 ata) increased the maximal density of microbial colonies and decreased the colony size as compared with cultivation in argon only.

[Investigation of the main gas-exchange parameters in the Mongolian gerbil in view of a space experiment].

A pressurized module with a self-sustained life support system is being designed for spaceflight experiments with Mongolian gerbils (Meriones unguiculatis). As a rule, these rodents do not drink free water taking minimum of water available in nourishment Although the gerbil is a common test object, it has never been flown in space. Specifically, nothing is known about the animal gas-exchange parameters critical for the development of life support systems. Our purpose was to shed light on the gerbil's gas-exchange demands and thereupon to prototype the air supply system in simulation experiments. On the average, a group of (n = 9, mean body mass of 45 g) consumed 0.044 ml/g/min of oxygen and produced 0.024 ml/g/min of CO2. The proposed design of the animal gas supply system controls oxygen and carbon dioxide at the atmospheric concentrations. Data of these experiments were used to write specifications for animals maintenance module KONRTUR to be launched aboard space vehicle FOTON-M.

[Influence of increased partial argon and nitrogen pressure on the R-plasmid Escherichia coli transfer frequency].

Subject of the study was frequency of transfer of bacterial plasmids determining the antibiotic resistance (R-plasmid) in argon-containing gas mixtures. Investigated were reference strains of Escherichia coli K-12. Conjugation took place during incubation in pAr/pN2/pO2, ata (1 ata = 10(5) kPa): No. 1 - 0.0/0.8/0.2 (air control); No. 2 - 1.0/0.8/0/2; No. 3 - 0.0/1.8/0.2; No. 4 - 1.0/1.8/0.2. E.coli conjugation was found inhibited after 24 hrs. of incubation with pAr elevated to 1 ata, whereas elevated partial pressure of argon (1 ata) and nitrogen (1.8 ata) brought transfer frequency down to the minimum.

Microbial utilisation of natural organic wastes.

The waste management strategy for the future should meet the benefits of humanity safety, respect principals of planet ecology, and compatibility with other habitability systems. For these purpose the waste management technologies, relevant to application of the biodegradation properties of bacteria are of great value. The biological treatment method is based upon the biodegradation of organic substances by various microorganisms. The advantage of the biodegradation waste management in general: it allows to diminish the volume of organic wastes, the biological hazard of the wastes is controlled, and this system may be compatible with the other systems. The objectives of our study were: to evaluate effectiveness of microbial biodegradation of non-pretreated substrate, to construct phneumoautomatic digester for organic wastes biodegradation, and to study microbial characteristics of active sludge samples used as inoculi in biodegradation experiment. The technology of vegetable wastes treatment was elaborated in IBMP and BMSTU. For this purpose the special unit was created where the degradation process is activated by enforced reinvention of portions of elaborated biogas into digester. This technology allows to save energy normally used for electromechanical agitation and to create optimal environment for anaerobic bacteria growth. The investigations were performed on waste simulator, which imitates physical and chemical content of food wastes calculated basing on the data on food wastes of moderate Russian city. The volume of created experimental sample of digester is 40 l. The basic system elements of device are digesters, gas receiver, remover of drops and valve monitoring and thermal control system. In our testing we used natural food wastes to measure basic parameters and time of biodegradation process. The diminution rate of organic gained 76% from initial mass taking part within 9 days of fermentation. The biogas production achieved 46 l per 1 kg of substrate. The microbial studies of biodegradation process revealed following peculiarities: (i) gradual quantitative increasing of Lactobacillus sp. (from 10(3) to 10(5) colony forming units (CFU) per ml), (ii) activation of Clostridia sp. (from 10(2) to 10(4)CFU/ml), (iii) elimination of aerobic conventional pathogens (Enterobacteriaceae sp., Protea sp., staphylococci). The obtained results allow to evaluate effectiveness of proposed technology and to determine the leading role of lactobacilli and clostridia in process of natural wastes biodegradation. Our further investigations shall further be concentrated on creation of artificial inoculi for launching of food wastes biodegradation. These inoculi will include active and adapted strains of clostridia and lactobacilli.

[The effect of argon-containing hypoxic gas environment on development of Japanese quail embryos]. / Vozdeistvie argon-soderzhashchikh gipoksicheskikh gazovykh sred na razvitie émbrionov iaponskogo perepela.

In case of acute hypoxic hypoxia argon in the gas environment is favorable to survivability of laboratory animals (rats). Our purpose was to evaluate effects of an argon-containing hypoxic gas environment on embryogenesis of the Japanese quail (Cortunix cortunix japonica). Eggs of the Japanese quail were incubated in a pressurized chamber with a hypoxic gas environment differing in concentration of nitrogen and argon. In hypoxic (10% O2) oxygen-nitrogen and oxygen-nitrogen-argon atmospheres total mortality of embryos was observed no later than on day 7 of development. These gas mixtures also had a teratogenic effect. However, about 55% of argon in atmosphere prevented completely microcephalia and reduced in half incidence of other pathologies.

Sensitivity to hypobaric hypoxia in mice selected for high and low brain weights.

We studied the effect of hypobaric hypoxia on mice with various brain weights. Mice with low brain weight were more resistant to hypoxia than animals with high brain weight.

[Technology of biological management of plant and animal wastes]. / Tekhnologiia biologicheskoi utilizatsii otkhodov rastitel'nogo i zhivotnogo proiskhozhdeniia.

Analytical, research and design efforts were made to modify the technology of anaerobic fermentation of plant and animal wastes. Results were publication of a register of wastes of a middle size Russian town, development of a simulator of natural food wastes, and development and testing of a laboratory prototype of original system for anaerobic degradation of natural food wastes. It was shown that association of Clostridia and lactobacilli is best to initiate and implement the first phase of biodegradation of natural wastes.