Relationship between neurophysiological indices of cognitive processes and MRI characteristics of some brain structures in healthy subjects and patients with schizophrenia

The relationships between the parameters of waves of auditory event-related potentials (ERPs) in the oddball paradigm and the volumes of the hippocampus, amygdala, and caudate nuclei were analyzed in healthy subjects and patients with schizophrenia. The data obtained suggest that faster mental processes and stronger activation and/or synchronization of the activity of ERP wave generators in healthy subjects correspond to smaller volumes of the structures studied. The structure of the relationships in patients with schizophrenia differed from the normal one; significant correlations were observed with the volume of the caudate nuclei, and more pronounced “normalization” of neurophysiological characteristics was associated with large volumes of these structures.     

Ecological-cenotic role of phytogenous fields of Scots pine on coal dumps

Transformation of ecological factors on dumps of coal mines under the effect of Pinus sylvestris L. results in formation of three-zone phytogenous fields. The under-crown zone is characterized by a leveled temperature regime, low illumination, forest litter accumulation, and formation of abundant undergrowth. In the sufficiently moistened transitional zone, well-developed moss cover is formed, and the undergrowth occurrence is very low. The external zone, transitional to the background meadow communities, is characterized by well-formed grass cover, an abundance of species, and a group pattern of the undergrowth of P. sylvestris L. The reaction of herbaceous plants on the effect of phytogenous pine fields may be positive (adaptive) or negative. Most species are characterized by a negative reaction.     

Potassium fluxes, energy metabolism, and oxygenation in intact diabetic rat hearts under normal and stress conditions

We evaluated the function of Na(+)/K(+) ATPase and sarcolemmal K(ATP) channels in diabetic rat hearts. Six weeks after streptozotocin (STZ) injection, unidirectional K(+) fluxes were assayed by using (87)rubidium ((87)Rb(+)) MRS. The hearts were loaded with Rb(+) by perfusion with Krebs-Henseleit buffer, in which 50% of K(+) was substituted with Rb(+). The rate constant of Rb(+) uptake via Na(+)/K(+) ATPase was reduced. K(ATP)-mediated Rb(+) efflux was activated metabolically with 2,4-dinitrophenol (DNP, 50 micromol.L(-1)) or pharmacologically with a K(ATP) channel opener, P-1075 (5 micromol.L(-1)). Cardiac energetics were monitored by using (31)P MRS and optical spectroscopy. DNP produced a smaller ATP decrease, yet similar Rb(+) efflux activation in STZ hearts. In K(+)-arrested hearts, P-1075 had no effect on high-energy phosphates and stimulated Rb(+) efflux by interaction with SUR2A subunit of K(ATP) channel; this stimulation was greater in STZ hearts. In normokalemic hearts, P-1075 caused cardiac arrest and ATP decline, and the stimulation of Rb(+) efflux was lower in normokalemic STZ hearts arrested by P-1075. Thus, the Rb(+)efflux stimulation in STZ hearts was altered depending on the mode of K(ATP) channel activation: pharmacologic stimulation (P-1075) was enhanced, whereas metabolic stimulation (DNP) was reduced. Both the basal concentration of phosphocreatine ([PCr]) and [PCr]/[ATP] were reduced; nevertheless, the STZ hearts were more or equally resistant to metabolic stress.     

Visualization and grading of regional ischemia in pigs in vivo using near-infrared and thermal imaging

Reductions in regional coronary flow result in tissue deoxygenation and decrease in surface temperature, changes detectable by near-infrared spectroscopic (NIRS) and thermal imaging, respectively. In anesthetized open-chest pigs, an inflatable occluder and flow probe were placed around the left anterior descending artery. Gated NIRS and nongated thermal images were acquired at baseline, partial (17% and 50%), and complete occlusion and reflow. At each step, dobutamine was infused (10 microg.min(-1).kg(-1)) for 7-9 min to increase blood pressure and flow. Changes in the oxygen saturation parameter, rate of indocyanine green flow tracer passage, and the surface temperature were correlated with the measured left anterior descending artery flow. Location and sizes of the areas of reduced oxygenation, indocyanine green uptake, and temperature were similar. Decrease in the coronary flow to 50% and 17% of baseline resulted in progressive decrease in the above parameters, whereas increase in flow from 75% to approximately 250% achieved by dobutamine and reactive hyperemia did not significantly change them. Dobutamine increased total and epicardial flow in ischemic areas and increased subepicardial oxygenation. NIRS and thermal imaging provide epicardial maps of oxygen saturation and perfusion that reveal ischemic areas. Combination of these techniques may be useful in the coronary artery bypass graft (CABG) surgery setting.     

Ratio of plants with various mycorrhizal statuses at overgrown rock dumps

The abundance of plants with various mycorrhizal statuses has been analyzed during the endoecogenetical overgrowth succession at the overburden rocks of the Fedorovskii open-pit mine (Karaganda, Kazakhstan). The abundance of obligate arbuscular mycorrhiza-forming plants increases. The ratio between plants with various mycorrhizal statuses stabilizes between the 10th–20th years of overgrowth, thereafter undergoing insignificant changes.     

Transition of entheropathogenic and saprotrophic bacteria in the niche cycle: Animals-excrement-soil-plants-animals

The possibility of transition of saprotrophic and enteropathohenic bacterial populations following the chain of naturally related habitats—fodder-animal gastrointestinal tract (GIT)-animals excrement-soil-plants and again animals with a cyclic formation—has been investigated quantitatively. All bacteria used in the experiments have been shown to successfully overcome all the mechanical, physical-chemical, and biological barriers in the food chain and to come out into the environment with a quite high number. It has been demonstrated that the same bacterial population can pass the whole cycle without additional introduction of similar populations from the outside.     

NIR spectroscopic imaging to map hemoglobin + myoglobin oxygenation,their concentration and optical pathlength across a beating pig heart during surgery

The purpose of this paper is to demonstrate that near‐infrared (NIR) spectroscopic imaging can provide spatial distribution (maps) of the absolute concentration of hemoglobin + myoglobin, oxygen saturation parameter and optical pathlength, reporting on the biochemico‐physiological status of a beating heart in vivo. The method is based on processing the NIR spectroscopic images employing a first‐derivative approach. Blood‐pressure‐controlled gating compensated the effect of heart motion on the imaging. All the maps are available simultaneously and noninvasively at a spatial resolution in the submillimeter range and can be obtained in a couple of minutes. The equipment has no mechanical contact with the tissue, thereby leaving the heart unaffected during the measurement. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Phosphocreatine production coupled to the glycolytic reactions in the cytosol of cardiac cells

Phosphocreatine production catalyzed by a cytosolic fraction from cardiac muscle containing all glycolytic enzymes and creatine kinase in a soluble form has been studied in the presence of creatine, adenine nucleotides and different glycolytic intermediates as substrates. Glycolytic depletion of glucose, fructose 1,6-bis(phosphate) and phosphoenolpyruvate to lactate was coupled to efficient phosphocreatine production. The molar ratio of phosphocreatine to lactate produced was close to 2.0 when fructose 1,6-bis(phosphate) was used as substrate and 1.0 with phosphoenolpyruvate. In these processes the creatine kinase reaction was not the rate-limiting step: the mass action ratio of the creatine kinase reaction was very close to its equilibrium value and the maximal rate of the forward creatine kinase reaction exceeded that of glycolytic flux by about 6-fold when fructose 1,6-bis(phosphate) was used as a substrate. Therefore, the creatine kinase raction was continuously in the state of quasiequilibrium and the efficient synthesis of phosphocreatine observed is a result of constant removal of ADP by the glycolytic system at an almost unchanged level of ATP ([ATP] ? [ADP]), this leading to a continuous shift of the creatine kinase equilibrium position.When phosphocreatine was added initially at concentrations of 5–15 mM the rate of the coupled creatine kinase and glycolytic reactions was very significantly inhibited due to a sharp decrease in the steady-state concentration of ADP. Therefore, under conditions of effective phosphocreatine production in heart mitochondria, which maintain a high phosphocreatine: creatine ratio in the myoplasm in vivo, the glycolytic flux may be suppressed due to limited availability of ADP restricted by the creatine kinase system. The possible physiological role of the control of the glycolytic flux by the creatine kinase system is discussed.