Pre-Holocene Taymyr Mammoth Petya: Mineralogical, Isotope, and Geochemical Properties of Bones, Soft Tissues, Skin, and Hair and Paleoecological Reconstructions.

New remains of a Taymyr mammoth, including bones, bone collagen, hairs, skin, and soft (muscle and fat) tissues were studied comprehensively by mineralogical, spectroscopic, chromatographic, and isotope-geochemical methods. The results were used to infer the mammoth's biological age and diet, paleoclimatic conditions, and the mechanisms and degree of fossilization of the remains.

Yersinia pestis Surface Antigens in Reception of Specific Bacteriophages.

The significance of Yersinia pestis surface antigens in adhesiveness to specific bacteriophages has been studied with the use of two methodological approaches. It was shown that Ail protein immobilized on the surface of polystyrene microspheres (but not in the solution), can bind both the Pokrovskaya phage and pseudotuberculous diagnostic phage. YapF autotransporter interacted with both phages in a water-soluble form, but YapF bound to polystyrene microspheres interacted only with the Pokrovskaya phage.

Effects of Succinate-Containing Preparation on Characteristics of Rat Erythrocytes in Exhaustive Swimming with a Load.

We studied the dynamics of the red blood cell composition of Wistar male rats at rest and when swimming with a load (4% body weight) before and after administration of a succinatecontaining preparation (meso-2,3-dimercaptosuccinic acid). In rats receiving the succinatecontaining preparation, a decrease in the number of red blood cells and an increase in their volume and absolute and relative number of reticulocytes were observed at rest in comparison with vivarium control. In rats exposed to exhaustive swimming after preliminary administration of the test preparation (12 h before the test), we observed a decrease in hematocrit and erythrocyte diameter in comparison with the corresponding parameters in rats not treated with the preparation; the level of hemoglobin did not change.

Outer Membrane Vesicles as Potential Vaccine Candidates in Protecting against Plague.

Despite the relatively low incidence of plague, its etiological agent, , is an exceptional epidemic danger due to the high infectivity and mortality of this infectious disease. Reports on the isolation of drug-resistant strains indicate the advisability of using asymmetric responses, such as phage therapy and vaccine prophylaxis in the fight against this problem. The current relatively effective live plague vaccine is not approved for use in most countries because of its ability to cause heavy local and system reactions and even a generalized infectious process in people with a repressed immune status or metabolic disorders, as well as lethal infection in some species of nonhuman primates.

[Key Molecular Mechanisms of Aging, Biomarkers, and Potential Interventions].

The mechanisms of aging are described at the molecular, cell, tissue, and systemic levels. Primary age-dependent molecular lesions activate the cell stress response to compensate for the resulting defects, but the mechanisms that recover and maintain homeostasis are gradually deteriorated. When the amount of errors reaches a critical threshold in regulatory networks, a phase transition from health to disease occurs at the systemic level.

Changes in Total Cholesterol and Heart Rate in Normotensive and Hypertensive Rats under Combined Influence of Cold Exposure and Hypokinesia.

We studied the effect of hypokinesia alone and in combination with cold exposure on HR and total cholesterol content in the blood serum of Wistar, WKY, and SHR rats. Irrespectively of the season, hypokinesia was associated with a decrease in HR, which is probably a result of reduced body needs due to deceleration of metabolic processes. A significant increase in total cholesterol was found under conditions of cold exposure combined with hypokinesia, which indicates qualitative structural rearrangement of energy metabolism under the influence of environmental factors.

The role of carbonic anhydrase α-CA4 in the adaptive reactions of photosynthetic apparatus: the study with α-CA4 knockout plants.

The role of α-carbonic anhydrase 4 (α-CA4) in photosynthetic machinery functioning in thylakoid membranes was studied, using Arabidopsis thaliana wild type plants (WT) and the plants with knockout of At4g20990 gene encoding α-CA4 (αCA4-mut) grown both in low light (LL, 80 μmol quanta m s) or in high light (HL, 400 μmol quanta m s). It was found that a content of PsbS protein, one of determinants of non-photochemical quenching of chlorophyll fluorescence, increased in mutants by 30% and 100% compared with WT plants in LL and in HL, respectively. Violaxanthin cycle pigments content and violaxanthin deepoxidase activity in HL were also higher in αCA4-mut than in WT plants.

Irregular Ventricular Tachycardia as a Mechanism of Stabilization of Mechanoelectrical Processes in Canine Heart under Conditions of Antiorthostatic Hypokinesia.

We studied electrophysiological mechanisms of ventricular arrhythmias in dogs (n=7) under conditions of antiorthostatic hypokinesia (head-down tilt 45°). Abnormal transmural heterogeneity of repolarization in the base and apex of the left ventricle and increased dispersion of myocardial repolarization were revealed. By minute 30 of antiorthostatic hypokinesia, an increase in the duration of repolarization was revealed after a period of ventricular arrhythmia in all segments and regions of heart ventricles, which was accompanied by impairment of the pumping function of the heart.

Neuroprotective Effects of Dibornol in Focal Cerebral Ischemia/Reperfusion in Rats.

Neuroprotective activity of 2,6-diisobornyl-4-methylphenol (Dibornol) was studied under conditions of experimental focal cerebral ischemia/reperfusion modeled by intraluminal occlusion of the left middle cerebral artery for 1 h followed by recirculation. Dibornol administered in a dose of 10 mg/kg intragastrically 24 h and 30 min before and 24 h after focal ischemia/reperfusion modeling reduced the size of the brain infarction zone by 52% (48 h after recirculation) and neurological deficit by 1.7-2.

A Mass Burial of Fossil Lions (Carnivora, Felidae, Panthera (Leo) ex gr. fossilis-spelaea) from Eurasia.

The vertebrate fauna from the cave deposits in Imanai Cave in the Southern Urals (53°02' N, 56°26'E) has been studied. It contains 715 bones that belonged to at least 11 individuals of fossil lion (Panthera (Leo) ex gr. fossilis-spelaea).

Neuroprotective Activity of D-HES in Transient Global Cerebral Ischemia in Rats.

We studied the effect of O-((((4-hydroxy-3,5-di(1,7,7-trimethylbicyclo[2.2.1]hept-exo-2-yl) benzyl)oxy)ethyl)-O-(2-hydroxyethyl)-(1→4)-α-D-glucan (D-HES, 80 mg/kg, intravenously) and reference preparation ethylmethylhydroxypyridine succinate (EMHP-S, 50 mg/kg, intravenously) on rat survival and neurological deficit in 24 h after transient global cerebral ischemia in Wistar rats.

Isoprenaline Impairs Contractile Function of Ventricular Myocardium in Common Frog (Rana temporaria).

The contractile function of the heart was studied in adult frogs Rana temporaria under the influence of a toxic dose of isoprenaline under conditions of natural sinoatrial rhythm and during heart pacing. The dynamics of ventricular pressure was recorded with a Prucka MacLab 2000 instrument via a catheter introduced into the ventricle through the ventricular wall. Reduced (p<0.

Cardioprotective Activity of 2,6-Diisobornyl-4-Methylphenol in Acute Myocardial Ischemia/Reperfusion in Rats.

We studied the cardioprotective effect of 2,6-diisobornyl-4-methylphenol under conditions of myocardial ischemia/reperfusion in rats. Daily administration of 2,6-diisobornyl-4-methylphenol (100 mg/kg intragastrically) over 3 days before and 5 days after modeling of myocardial ischemia/reperfusion prevented the increase in the infarction area by almost 2 times in comparison with the control by day 5 after recirculation. The type and severity of pathological changes in ECG parameters reflecting necrotic changes in the myocardium under the action of the compound significantly decreased by day 35 of the experiment.

Specific Features of Depolarization of the Left and Right Atria in Rats with Alcoholic Cardiomyopathy.

Using a translation model of alcoholic cardiomyopathy in rats we showed the presence of an additional abnormal excitation focus in the area of the pulmonary vein lacunae in the left atrium and enhanced heterogeneity of the atrium depolarization pattern. These changes can determine electric instability of the myocardium and induce malignant heart rhythm disturbances including, sudden cardiac death.

Influence of Specific Bacteriophage on the Level of Vesicle Formation and Morphology of Cells of Yersinia pseudotuberculosis.

Incubation of Yersinia pseudotuberculosis cells grown on a solid medium with pseudotuberculous diagnostic bacteriophage for 20 min at 37oC led to a significant decrease in the concentration of both components of the system. This effect was absent when the bacteria were grown in a fluid medium. At the same time, this incubation regimen promoted vesicle formation and typical morphological changes in bacteria grown in both surface and suspension cultures.

Atria Depolarization in Rats with Alcoholic Cardiomyopathy.

Chronotopography of atrial subepicardium depolarization has been studied in a rat model of alcoholic cardiomyopathy. Formation of independent sources of initial atrial activity has been detected in the right and left atria. These sources induced the formation of several depolarization fronts that propagated autonomously, and this can be regarded as the cause of atrial arrhythmia.

Effect of Nanocrystalline Particles of Chitin on Blood Components in Humans and Experimental Animals.

Nanocrystalline particles of chitin in the form of hydrosol in a concentration of 0.63 mg/ml have no effect on aggregation of human platelets and clotting time of platelet-poor plasma in coagulation tests. ADP-induced aggregation of human platelets was inhibited by these nanoparticles in concentrations of 0.

Seasonal variations of leaf chlorophyll-protein complexes in the wintergreen herbaceous plant Ajuga reptans L.

The chlorophyll and carotenoid content, and the spectra of low-temperature fluorescence of the leaves, chloroplasts and isolated pigment-protein complexes in the perennial herbaceous wintergreen plant Ajuga reptans L. (bugle) in different seasons of the year were studied. During winter, these plants downregulate photosynthesis and the PSA is reorganised, including the loss of chlorophyll, possible reductions in the number of functional reaction centres of PSII, and changes in aggregation of the thylakoid protein complexes.

Pumping Function of Heart Ventricles in Different Mammalian Species under Conditions of Electrical Cardiostimulation.

Pumping function of the heart ventricles under conditions of electrical stimulation was examined in adult dogs and rabbits. Pacing induced different changes in intracardiac hemodynamics manifested in impairment of pumping function of the right ventricle, which is largely determined by the functional state of the left ventricle. Initially high HR in rabbits more deeply limited functional reserve of the myocardium in response to electrical stimulus and was accompanied by more pronounced disturbances of pumping function of both ventricles.

Effect of Pectin Gel Particles on Endotoxemia Induced by Restraint Stress in Mice.

We studied the effect of pectin gel particles on endotoxemia in mice induced by restraint stress. It was shown that the concentration of LPS in mouse blood increased during restraint stress, which was associated with memory impairment. Pectin gel particles prevented the development of stress-induced endotoxemia and memory impairment in mice.

Bioavailability of the Phenolic Antioxidant 4-Methyl-2,6-Diisobornylphenol After Oral Administration.

We compared bioavailability of 4-methyl-2,6-diisobornylphenol after single intragastric administration to rats in a dose of 200 mg/kg in starch suspension and in almond oil. Absorption of 4-methyl-2,6-diisobornylphenol in the gastrointestinal tract after administration in almond oil was much more efficient than after administration in aqueous starch mucus.

Photosynthetic activity of vascular bundles in Plantago media leaves.

Photosynthetic processes in the leaf lamina and midribs of Plantago media were investigated using plants grown in high light (HL) or low light (LL) conditions. The fluorescence parameters, which indicate photochemical/photosynthetic activity, were different in HL and LL grown plants, but no major differences between lamina and midribs were found. An OJIP test (chlorophyll a fluorescence transient induction) of LL grown plants, indicative of the chloroplast electron transport chain, also showed both tissues to be similar.

Repolarization of Heart Ventricles in Dogs during Recovery after Antiorthostatic Hypokinesia.

Repolarization properties of ventricular myocardium were studied in anesthetized adult dogs of both sexes subjected to antiorthostatic hypokinesia (head-down tilt at 45° and 60° to the horizontal) and during recovery period (horizontal position for 15 min). The time of repolarization of ventricular myocardium during recovery surpassed the initial value, which represents an adaptive response of the heart to antiorthostasis.

Immunochemical Nature of Receptors of Pseudotuberculosis Diagnostic Bacteriophage.

The effect of treatment of Yersinia pseudotuberculosis cells with antibodies of various specificities on adhesiveness of pseudotuberculosis bacteriophage was analyzed by competitive inhibition technique. Bacteriophage adsorption to bacteria was sterically inhibited by monoclonal antibodies to protein epitopes of Y. pseudotuberculosis outer membrane.