[Dynamics of Purple Sulfur Bacteria in a Meromictic Saline Lake Shunet (Khakassia, Siberia) in 2007-2013].

According to the results of seasonal monitoring, in 2007-2013 purple sulfur bacteria morphologically similar to Thiocapsa sp. Shira_1 (AJ633676 in EMBL/GenBank) predominated in the anoxygenic phototrophic community of the water column of the meromictic Lake Shira (Khakassia, Siberia). No pronounced seasonal periodicity in the total cell number in the water column was revealed during the period of observation. In some years cell number during the period when the lake was covered with ice was reliably higher than in summer. The absence ofseasonal periodicity was probably due to the low amplitude of seasonal variations in temperature and illumination in the redox zone, resulting from its relatively deep location (12-16 m). The year-to-year dynamics was characterized by a reliable decrease of the total cell number in 2009-2010 and maxima in 2007 and 2011-2012. Canonical correlation analysis revealed that water temperature in the redox zone was the best predictor of the PSB abundance in Lake Shira. Water temperature, in turn, depended on the depth of mixing of the water column. Intense mixing in 2009-2011 was probably responsible for decreased PSB abundance in the lake. On the other hand, the absence of deep winter mixing, resulting in stable conditions in the chemocline, favored the preservation of relatively high PSB biomass. Prediction of circulation depth, which.depends mainly on the weather conditions and dynamics of the water level, is required for prediction of PSB abundance in Lake Shira. These results may be useful for paleolimnological reconstructions of the history of the lake based on the remnants of purple sulfur bacteria in bottom sediments.

[Specific features of nucleic acid synthesis in mitochondria of Elymus sibiricus from different natural populations]. / Osobennosti sinteza nukleinovykh kislot v mitokhondriiakh pyreinika sibirskogo (Elymus sibiricus) raznykh prirodnykh populiatsii.

Conditions and kinetic characteristics of nucleic acid synthesis were studied in the isolated mitochondria of Elymus sibiricus from different natural populations. The results showed the reciprocal dependence of RNA and DNA synthesis rates in the mitochondrial genetic system of E. sibiricus seedlings of different genotypes.

Influence of stress protein CSP 310 and antiserum against this protein on oxygen uptake, lipid peroxidation, and temperature of winter wheat seedling shoots during cold stress.

It is determined that infiltration of winter wheat seedling shoots by anti-CSP 310 antiserum caused a significant decrease of oxygen uptake in winter wheat shoots during short-term cold stress. On the other hand, infiltration of winter wheat seedling shoots by stress protein CSP 310 caused an increase of oxygen consumption. The comparison of the influence of infiltration of winter wheat shoots by CSP 310 and anti-CSP 310 antiserum on the rate of lipid peroxidation showed that, if infiltration by CSP 310 caused a decrease of conjugated diene formation, infiltration by anti-CSP 310 antiserum did not cause any significant changes in the rate of lipid peroxidation. The study of the influence of infiltration of winter wheat shoots by CSP 310 and anti-CSP 310 antiserum on the temperature of winter wheat shoots during cold stress showed that CSP 310 caused the increase of their temperature while anti-CSP 310 caused a decrease of their temperature.

Influence of CSP 310 and CSP 310-like proteins from cereals on mitochondrial energetic activity and lipid peroxidation in vitro and in vivo.

BACKGROUND: The development of chilling and freezing injury symptoms in plants is known to frequently coincide with peroxidation of free fatty acids. Mitochondria are one of the major sources of reactive oxygen species during cold stress. Recently it has been suggested that uncoupling of oxidation and phosphorylation in mitochondria during oxidative stress can decrease ROS formation by mitochondrial respiratory chain generation. At the same time, it is known that plant uncoupling mitochondrial protein (PUMP) and other UCP-like proteins are not the only uncoupling system in plant mitochondria. All plants have cyanide-resistant oxidase (AOX) whose activation causes an uncoupling of respiration and oxidative phosphorylation. Recently it has been found that in cereals, cold stress protein CSP 310 exists, and that this causes uncoupling of oxidation and phosphorylation in mitochondria. RESULTS: We studied the effects of CSP 310-like native cytoplasmic proteins from a number of cereal species (winter rye, winter wheat, Elymus and maize) on the energetic activity of winter wheat mitochondria. This showed that only CSP 310 (cold shock protein with molecular weight 310 kD) caused a significant increase of non-phosphorylative respiration. CSP 310-like proteins of other cereals studied did not have any significant influence on mitochondrial energetic activity. It was found that among CSP 310-like proteins only CSP 310 had prooxidant activity. At the same time, Elymus CSP 310-like proteins have antioxidant activity. The study of an influence of infiltration by different plant uncoupling system activators (pyruvate, which activates AOX, and linoleic acid which is a substrate and activator for PUMP and CSP 310) showed that all of these decreased lipid peroxidation during cold stress. CONCLUSIONS: Different influence of CSP 310-like proteins on mitochondrial energetic activity and lipid peroxidation presumably depend on the various subunit combinations in their composition. All the plant cell systems that caused an uncoupling of oxidation and phosphorylation in plant mitochondria can participate in plant defence from oxidative damage during cold stress.

An influence of stress protein CSP 310 and antiserum against this protein on lipid peroxidation in cereal mitochondria.

It is determined that an addition of an anti-CSP 310 antiserum to isolated winter wheat and maize mitochondria caused more significant increasing of spontaneous lipid peroxidation than the addition of stress protein CSP 310. It is shown that, at function of different mitochondrial respiratory chain complexes, the lipid peroxidation in winter wheat and maize mitochondria take place with different intensities. Under the functioning of mitochondrial respiratory chain complex IV, the maximum output of lipid peroxidation products, dienic conjugates is detected. The presence of antiserum against CSP 310 in incubation media induces lipid peroxidation more than the presence of CSP 310 in mitochondria isolated from stressed plants under these conditions. Based on data obtained, it is possible to conclude that in vivo endogenous CSP 310, during a cold stress, has an antioxidant activity the same as other known uncoupling proteins.

The search for proteins with immunochemical affinity to plant stress proteins at cold-adapted endemic Baikal fishes.

The search for proteins with immunochemical affinity to plant stress proteins in endemic Baikal fishes shows the presence of proteins, immunochemically related to plant heat-stabile proteins and plant uncoupling protein CSP 310. Western blotting showed that among the native cytoplasmic proteins of endemic Baikal fishes there are proteins immunochemically related to heat-stabile plant proteins with molecular weights about 480, 200-290, 150, 140 and about 90-100kD. SDS-electrophoresis showed the presence of polypeptides with molecular weights 23, 17 and 14kD in all species investigated and an additional 35kD polypeptide in Cottocomephorus grewingki. The search for polypeptides with immunochemical affinity to plant stress uncoupling protein CSP 310 in endemic Baikal fishes shows the presence of a 14kD polypeptide, immunochemically related to it.

[The complications of open mitral commissurotomy under moderate hypothermia]. / Oslozhneniia otkrytoi mitral'noi komissurotomii pri operatsiiakh v usloviiakh umerennoi gipotermii.

A comparative assessment of the postoperative period in 212 patients was made. Open mitral commissurotomy was performed under conditions of hypothermia without perfusion. Operations were fulfilled on 82 patients under conditions of craniocerebral hypothermia (the first group of patients, lethality 3.6%), on 130 patients under conditions of general moderate hypothermia (the second group, lethality 3.1%). Complications in the groups in question were not substantially different, although the amount of patients without complications was more in the first group (75.6%) than in the second group (44.6%). Complications after open mitral commissurotomy under conditions of hypothermia without perfusion were not specific for the methods under study and are known to occur after any cardiosurgical procedures. Open mitral commissurotomy performed under conditions of both general and craniocerebral moderate hypothermia was followed by few dangerous complications and not high lethality. Using these two variants of moderate hypothermia allows the completely adequate performance of open mitral commissurotomy to be fulfilled both in planned and in emergency operative interventions.