Search PubMed⌕ Search

Biomedical subjects

S V Lysenko

Publications and source records attributed to S V Lysenko.

At least 19 recordsLinked to original sources
PubMed1993

[The role of chlamydial infection in the genesis of tuboperitoneal sterility in women].

The incidence of chlamydial infection in women with tuboperitoneal sterility is 49.5%. Clinically inflammatory diseases of the pelvic organs in such an infection are characterized by a primary chronic course with frequent recurrences and involvement of the cervix uteri, urethra, internal genitals, with moderately manifest clinical symptoms. Therapy of chlamydial infection should be combined with individual selection of therapeutic measures with due consideration for the inflammatory process phase and site, for the type of pathologic changes, general and immune status.

Adult↗
PubMed1992

An approach to the detection of microbe life in planetary environments through charge-coupled devices.

The use of charge-coupled devices is suggested as a means for detecting growth of micro-organism colonies. The accuracy of the method is determined by channel width and the sensitivity by the signal/noise ratio. The method was tested on a dense nutrient medium, which is to be considered more suitable to micro-organisms of the dry Martian soil than the water solution of nutrients employed in the Viking's strategy.

Culture Media↗
PubMed1992

Drying as one of the extreme factors for the microflora of the atmosphere.

An investigation of the effects of drying and drying-rewetting cycles under vacuum conditions of 10(-2) torr at -30 degrees C on conidia of the atmospheric strain Penicillium chrysogenum from 48-77 km heights, collected by meteorological rockets found that survival and restoration of the initial physiological properties were possible through some very efficient protective cellular mechanisms. Such adaptive possibilities explain the widespread diffusion of microbial cells throughout the biosphere of our planet.

Atmospheric Pressure↗
PubMed1991

[Microorganisms synthesizing enzymes with thrombolytic action].

The literary and experimental data obtained by the authors concerning the ability of various microorganisms to synthesize exoproteases lysing the thrombi of human blood are presented in the article. Various methods of enhancing the thrombolytic activity of microorganisms cultures, the properties of some isolated and purified preparations, methods of enlarging the specificity of the enzymes to fibrin and of reduction of their toxicity are considered.

Bacteria↗
PubMed1989

[The effect of drying on the content of nucleic acids and mutational changes in microorganisms].

The literary and own experimental data on the genetic apparatus changes in microorganisms after drying are reviewed. In the survived drying cells the total content of nucleic acids decreases, some amount of mainly high-molecule ribonucleic acid decomposes. The RNA isolation into the suspended medium is also observed in connection with the destructive processes in the cytoplasmic membrane and the decomposition of some intracellular structures. The dehydration of microbial cells violates the normal processes of DNA replication, and sometimes it leads to the conformational changes in molecule structure. In some cases the damage in the genetic apparatus causes the mutation changes of microorganisms. This should be taken into account in experiments where lyophilized cultures are used.

DNA Replication↗
PubMed1979

Microorganisms of the upper layer of the atmosphere and the protective role of their cell pigments.

Of the six species of microorganisms isolated from the mesosphere, five contained pigments and were more resistant to UV radiation compared with their pigment-free mutants. The black pigment isolated from the conidia of Aspergillus niger considerably increased the UV resistance of the unpigmented mutant conidia of Penicillium notatum, the spore Circinella muscae and the vegetative cells of Micrococcus albus. From the data it is possible to conclude that in the upper layers of the Earth's atmosphere the predominant proportion of pigmented microorganisms is the consequence of natural selection by UV radiation.

Air Microbiology↗
PubMed1978

Upper boundary of the biosphere.

By using meterological rockets fitted with specially designed analyzers, samples for microbiological investigation have been taken. The analyzer design prevented extraneous microorganisms from penetrating into the analyzer. Before being used, the analyzers were sterilized with high gamma-ray doses. For the first time microorganisms have been detected in the mesosphere at an altitude of 48 to 77 km. The microorganisms are microscopic fungi having black conidia or spores (Circinella muscae, Aspergillus niger, Papulaspora anomala) and one species forming green conidia (Penicillium notatum). Colonies of Mycobacterium luteum and Micrococcus albus have also grown. Five of the six species have synthesized pigments. The presence of pigmented microbial forms leads us to believe that natural selection is occurring in the mesosphere because cells possessing chromogenous pigments (carotenoids, melanins) are more resistant to ultraviolet-ray action. A greater number of microorganisms have been registered in the mesosphere during dust storms than in the absence of strong winds.

Air Microbiology↗
PubMed1977

Resistance of stratospheric and mesospheric micro-organisms to extreme factors.

Studies of the stratosphere and mesosphere, by means of special analysers installed on meteorological rockets, have thrown more light on our knowledge of the upper boundary of the biosphere. The presence of the following micro-organisms was registered at heights of 49-77 km: Aspergillus niger, Penicillium notatum, Circinella muscae, Papulaspora anomala, Mycobacterium luteum and Micrococcus albus. The isolated micro-organisms were subjected to the action of gamma-irradiation, high vacuum and UV radiation in order to evaluate the quality of sterilization by gamma-rays (3.2-3.5 Mrad) prior to sampling and the resistance of these micro-organisms to physical factors of the stratosphere and mesosphere. No species with high radio-resistance were detected among the isolated cultures. The D10 index for fungal spores and bacterial vegetative cells, freeze-dried or suspended in a physiological solution, did not exceed 290 krad. These data confirm that sterilization of the analyser with gamma-rays assured the purity of biological experiments during sampling. The isolated micro-organisms were found to be very resistant to high vacuum (10(-9) mmHg) and UV radiation, with the exception of the pigmentless Micrococcus albus. This evidence shows that pigmented micro-organisms can survive in the earth's atmosphere at high altitudes.

Air Microbiology↗
PubMed1976

On micro-organisms of the stratosphere.

The lower parts of the biosphere are well studied since various live beings are found in oceans and at the bottom of large hollows. Contrary to this, we have no data about the upper boundaries of the biosphere. Samples were obtained with the help of specially constructed analysers which were installed in meteorological rockets and reached an altitude of 100 km. With the help of methods completely excluding the possibility of contamination of analysers with outside microflora it became possible to prove that earth microbes carried by air currents are present in the stratosphere. At an altitude of 48-77 km Circinella muscae, Asp. niger, Penicillium notatum were found as well as mycobacterium and micrococcus. The correlation of these cultures with external factors is studied and the weight of one conidium or one cell in isolated micro-organisms is estimated. These investigations will continue.

Air Microbiology↗
PubMed1971

The influence of ultra-high vacuum on crystalline enzymes.

The exploration of physical conditions in space is closely related to the study of the influence of space factors on biological objects. The study of high vacuum is of particular importance because its effects are as yet imperfectly understood. Micro-organisms are suitable models for these investigations. It has already been found that in reference to high vacuum, micro-organisms may be divided into two groups: resistant and nonresistant forms. Bacterial and actinomycetal spores and conidia of Aspergillus are classified as the resistant forms. Parallel with these, rod-shaped non-sporeforming bacteria, yeasts and conidia of Penicillium, were found to be non-resistant forms. The mechanism of resistance and death of micro-organisms under high vacuum is still not clearly understood. Because of this the investigation employing such important macromolecules as crystalline cytochrome C, catalase, peroxidase and ATP have been carried out. These compounds were exposed to a high vacuum (10(-8)-10(-9) mm Hg) over a period of 72 hours. Then the weighed samples taken from treated specimens and controls were dissolved firstly in a phosphate buffer solution (pH=6.8-7.2) and were then diluted by this buffer up to a concentration of 10(-9) mg ml. The solutions obtained were investigated by the chemiluminescent method. It was found that high vacuum effects gave rise to a slight decrease (up 7%) in enzyme activity in concentrated solutions and to a significant inactivation (up to 30%) in diluted ones.

Adenosine Triphosphate↗
PubMed1970

The effect of high vacuum on oxidative reactions in bacteria and the activity of certain enzymes.

Among the physical factors which might influence micro-organisms one of the most potentially interesting is high vacuum. The effect of high vacuum is less studied as compared with other physical factors. It is impossible to achieve, under laboratory conditions, a vacuum of the order 10(-16) mm Hg which is probably characteristic of space. Earlier, the effect of high vacuum was studied on different bacteria, yeasts, molds and algae. It appeared that spores and fungal conidia were not killed by high vacuum. Later, the effect of high vacuum on physiological processes in micro-organisms was studied. The ability to oxidize glucose or ethanol was studied with Sarcina flava and Bacillus simplex cells after they were subjected for 72 hr to vacuum (10(-8) to 10(-9) mm Hg). The oxidation rate was followed polarographically. The oxidative ability of S. flava cells diminished [correction of dimished] after their subjection to vacuum, while B. simplex spores were unchanged in that respect. The following crystalline enzymes were subjected for 72 hr to the same vacuum: alpha-amylase, catalase, ribonuclease, trypsine and urease. Then the activity of the above enzymes was tested on corresponding substrates. Not a single enzyme was totally inactivated. About 50% of activity was lost with alpha-amylase; 25--35% of activity with catalase, ribonuclease and urease. Trypsine retained its total activity. Thus, high vacuum cannot be listed among factors rapidly inactivating enzymes of micro-organisms.

Bacillus↗
PubMed1967

Exobiology and the effect of physical factors on micro-organisms.

A study of the action of different physical factors on micro-organisms is necessary for a further development of exobiology. The action of temperature on crystalline preparations of catalase and peroxidase was studied by means of oscillographic polarography. A determination of the height of polarographic waves at the decrease of temperature from 20 degrees C to 0 degrees C has shown that structural elements of the peroxidase molecule connected with the enzymatic activity are more stable with the decrease of temperature cf. catalase. A relative resistance of the dehydrogenase activity in Az. vinelandii cells to high vacuum was found. Incubation of azotobacter cells under vacuum of 10(-9) mm Hg during 72 hr did not decrease the activity of alcohol and succinic dehydrogenase. Bac. cereus spores can be preserved from bactericidal UV action by thin films of chrome. The thickness of chrome film being 200-670 angstroms, spores are killed by a dose of 7.8 x 10(7) erg/cm2 at 253.7 microns wave length. Spores covered by chrome film thicker than 800 angstroms remain alive after this treatment. Investigations carried out with an 'Artificial Mars' camera led to the following results. The growth of Bac. megaterium on liquid growth media in this camera ceases as a result of UV rays killing all cells after 3 weeks. Untreated bacteria grow in the camera for a long time. Spore-forming bacteria isolated from the sand of the Kara-Kum Desert grow in ground limonite (with the addition of 2% garden soil) having maximum hygroscopic humidity (3.8%). Freezing and thawing (from -60 degrees C to +25 degrees C) corresponding to day temperature deviations on Mars, low pressure (P=10 mm Hg) and the composition of the atmosphere (CO2-50%, N2-40%, Ar-10%) do not influence the growth of xerophylic bacteria under study. Humidity is the main factor limiting the growth of micro-organisms under 'Artificial Mars' conditions. According to the further development of the microbiological meteorite analysis methods, samples of rocks and stone meteorites were sterilized, incubated in the desert or on a snow surface in the Arctic and after different times (from 100 days to 7 months), investigated. In all cases, microbes were found only on the sample surfaces, whereas 1 cm from the surface and in the central parts micro-organism were completely absent. Hence, microbiological analysis of central parts of meteorites fallen in the Arctic or during dry periods of the year in the desert can give reliable results.

Alcohol Dehydrogenase↗
PubMed1966

The possibility of life in outer space.

Experiments were carried out dealing with the effect of extreme factors on microorganisms. Methods for microbiological analysis of meteorites were developed. The effect of temperature, from -20 degrees C to +15 degrees C, on trypsine activity was studied. It was shown that at about -3 degrees C a definite intramolecular reorganization occurs in the enzyme, leading to decreased activation energy. Previously reported resistance of microorganisms to high vacuum was confirmed. New species were tested at l0(-8)-10(-9) mm Hg. It was shown that very thin metal and metal oxide films, as well as films from other substances, may fully protect microorganisms from the hazardous effect of UV rays. By using an artificial climate, camera forms of microorganisms were selected which have the highest resistance to the whole complex of Martian climatic factors. Pigmented and spore-forming microorganisms resist UV up to a dose of 4.04 x 10(8) erg/cm2. There are microorganisms on Earth which show some activity in soil at a relative humidity of 0.096-0.196%. Preliminary data permit one to assume the possibility of existence of Earth-like forms on Mars. The majority of meteorites are accessible to Earth microorganisms. While choosing a meteorite for microbiological analysis it is necessary to consider the soil and climatic factors of the country where the latter has been found.

Bacillus↗
PubMed1965

Ultra-high vacuum and microorganisms.

Experimental study of the space environment effect on living organisms is one of the most important tasks of exobiology. However location of the living organisms under study outside space vehicles and sputniks is combined with technical difficulties. Therefore it is much more suitable to reproduce conditions found in space in laboratory and to study its effect on living cells. It was proved that low temperatures, even those approaching absolute zero do not kill microorganisms. The fact of microorganisms surviving radiation of some million roentgen suggests that they would not be killed by ionizing radiation in space. UV rays should be considered as the most active sterilizing agent. The ability of microorganisms to resist high vacuum is studied much worse. Under the action of high vacuum at 10(-8)-10(-9) mm Hg during 72 hours all studied seven species of spore-forming bacilli remained viable. As for nonsporeforming bacteria under conditions mentioned, cells of some species perished (correction of parished) completely while other species retained viable cells. Conidia of fungi and parts of mycelium of fungi which do not form conidia, sustained high vacuum well.

Aspergillus fumigatus↗
PubMedDate not supplied

[Specificity of action of extracellular proteases from Streptomyces spp].

The ability of an Actinomyces strain--Streptomyces spp. to produce extracellular proteases has been studied under varied cultivation conditions during the growth cycle. The activity of enzyme preparations precipitated from the culture liquid was determined with various substrates--gelatin, casein, fibrinogen, fibrin and collagen. The isolated enzyme complex possessed caseinolytic, fibrinolytic, thrombolytic and collagenolytic activities.

Caseins↗