Rate of endogenous respiration of Pseudomonas cells

A method is proposed for determining the rate of endogenous respiration in Pseudomonas cells grown under the conditions of batch cultivation. The method takes into account the dynamic characteristics of the gauge and of the secondary instrument. The rate of Pseudomonas endogenous respiration was shown to be at the beginning of the range established earlier for other bacteria.     

The epidemiology of the infection caused by the human immunodeficiency virus in the USSR

The existing system of the epidemiological surveillance of HIV infection in the USSR makes it possible to evaluate the present situation as the beginning of epidemic. The main routes of the transfer of HIV infection as per data for April 1989: 50% by the sexual route, 25.8% by parenteral manipulations.     

Hypotensive effect of Oxacom® containing a dinitrosyl iron complex with glutathione: Animal studies and clinical trials on healthy volunteers

A comparative study of hypotensive effects of binuclear forms of dinitrosyl iron complexes (DNICs) with glutathione, S-nitrosoglutathione (GS-NO) and sodium nitrite (NaNO₂) on rats has been carried out. The latter appeared to be the least efficient, viz., mean arterial pressure (MAP) decreased by 10 and 30 mm Hg at 25 and 100 μmoles/kg of NaNO₂. In contrast, DNIC and GS-NO produced an appreciable hypotensive effect when used at much lower concentrations. GS-NO reduced MAP to the same extent, viz., to 90 mm Hg, on a hundredfold dose scale (from 0.4 up to 50 μmoles/kg) with subsequent restoration of MAP within the next 6–15 min. A similar effect was observed for DNIC except that the amplitude of the MAP drop was lower and the duration of hypotension was essentially greater. DNIC with glutathione were selected as a basic material for pilot-scale production of a hypotensive drug (commercial name Oxacom®). Preliminary pharmacological testing of Oxacom did not establish any adverse or deleterious side effects.Clinical trials of Oxacom® were performed on 14 healthy male volunteers in whom single intravenous infusion of the drug (5 mg/kg or 0.2 μmoles/kg of DNIC, respectively) evoked a characteristic response manifested as a 3–4 min drop by 24–27 mm Hg of both diastolic and systolic AP with its subsequent slow restoration within the next 8–10 h. The heart rate was quickly normalized after an initial increase. Cardiac output was unchanged despite reduced cardiac filling. A comprehensive analysis of clinical and biochemical data failed to establish any significant pathological changes in these parameters. The data obtained suggest that Oxacom® can be recommended for the second phase of clinical trials.     

Ecological Monitoring of the Water Area of Port Vostochnyi (Wrangel Bay) in the Sea of Japan (1995–2002)

Benthic surveys carried out in 1989 (literature data), 1995, and 2001 (original data) revealed changes in the structure of soft bottom communities of Wrangel Bay (Peter the Great Bay, Sea of Japan), where a deep-water port of Vostochnyi is situated. The functioning of the port has caused no significant environmental pollution by heavy metals, hydrocarbons, and other pollutants. Bottom dredging and the siltation induced by it have drastically lowered the benthos biomass, changed benthic communities, and altered their trophic structure. Sestonophages have disappeared nearly altogether being replaced by detrivores. The ecological state of the benthos is characterized as unstable.     

The use of various models of biosynthesis kinetics]

The available models of the microorganism growth kinetics are analyzed. The possibility of application of the Monod model is studied. It is shown that these models do not permit describing adequately the experimental data at different initial concentrations of biomass and substrate that vary in a wide range. The calculations of the static modes of operation of biochemical react ors differ greatly.     

Forecasting of biocenosis quantity in the open system with a finite difference model]

A simple mathematical model for the dynamics of biocenosis in an open system was worked out. The model is based on the finite-difference presentation of experimental data. It also takes into account the past history of population development. The testing of the model proved its ability to forecast the density of populations in open systems.     

Effect of somatotropin on the course and result of combined radiation and mechanical injury

In the experiment on rats it was shown that injection of somatotropin (1 ED/kg, i.m. at 1, 3, 5, 7 and 9 days) after combined irradiation and mechanical injury (4.5 Gy, LD50/30 and plural fractures) improved the overall condition of the rats and increased the survival. The drug accelerated the bone regeneration.     

Macrobenthos of Accumulative Plains and Slopes of Ekspeditsii Bay (Pos'eta Bay,Sea of Japan)

The submarine accumulative plain of Ekspeditsii Bay is heterogeneous in terms of ground pattern and the composition and biomass of macrobenthos. The smallest values of the total biomass are characteristic of soft pelites (58.9 g/m²), siltstone pelites (55.9 g/m²), and pelites with an insignificant admixture of broken mollusk shells (108 g/m²). The greatest total biomass (649.2 g/m²) is registered around biogerms, in bottom areas composed of pelites with large fragments and entire valves of mollusk shells. On accumulative slopes of the bay, in the community of seagrasses, Zostera marina constitutes 90% of the biomass and macrofauna provides the remaining 10%. The values of the total biomass of macrobenthos of the accumulative plain and macroflora of the accumulative slopes of the bay are close to each other (about 12000 tons); however, both values are only 0.4 times as great as the biomass of macrobenthos on biogerms that occupy only 6.2% of the total bottom area in the bay.     

Autostabilization of the pH in a batch culture of Pseudomonas

Ranges within which the pH of the environment can be self-regulated have been determined for microorganisms belonging to the Pseudomonas genus. The ability of these microorganisms to self-regulate the pH was detected both at an increase and a decrease in the pH of the environment as compared to its optimal value. The rate of self-regulation appears to be proportional to the concentration of viable cells in a suspension. The results may be used for creating an economical system for maintaining the pH of the environment in industrial fermentation.     

Computer simulation of temperature autostabilization: an analysis of the phenomenon

A mathematical model of the temperature autostabilization by microorganism populations in batch and continuous operation has been developed. It adequately describes the process of temperature autostabilization by Candida tropicalis yeast microorganisms on H-alkanes. The model analysis has permitted determination of the conditions for the existence of the phenomenon and an explanation of its basic factors, such as linear biomass growth and dependence of microorganisms growth velocity on heat transfer through reactor walls. The industrial application of this interesting phenomenon is discussed. Correspondence to: M. Kristapsons