Dominant Frequency of Ventricular Fibrillation During Ischemia and Reperfusion.

Ventricular fibrillation (VF) in dogs is characterized by a rapid increase in its dominant frequency during the 1st minute of reperfusion followed by its decrease during the 2nd minute of reperfusion. The longer is ischemia in VF, the greater is the increase in dominant VF frequency during reperfusion. The 1st minute of reperfusion is characterized by a 1.2-fold increase in dominant VF frequency after 1-min ischemia in VF, by 1.4-fold increase after 2-min ischemia, by 2-fold increase after 3 min, and by 2.6-fold increase after 4-min ischemia. During the 2nd minute of reperfusion, the dominant VF frequency decreased by 1.1-1.3 times, and during 3rd-10th minutes of reperfusion, the dominant VF frequency is stabilized.

Expression of NLRP3 Inflammasomes in Neurogenic Niche Contributes to the Effect of Spatial Learning in Physiological Conditions but Not in Alzheimer's Type Neurodegeneration.

A common feature of neurodegenerative disorders, in particular Alzheimer's disease (AD), is a chronic neuroinflammation associated with aberrant neuroplasticity. Development of neuroinflammation affects efficacy of stem and progenitor cells proliferation, differentiation, migration, and integration of newborn cells into neural circuitry. However, precise mechanisms of neurogenesis alterations in neuroinflammation are not clear yet. It is well established that expression of NLRP3 inflammasomes in glial cells marks neuroinflammatory events, but less is known about contribution of NLRP3 to deregulation of neurogenesis within neurogenic niches and whether neural stem cells (NSCs), neural progenitor cells (NPCs) or immature neuroblasts may express inflammasomes in (patho)physiological conditions. Thus, we studied alterations of neurogenesis in rats with the AD model (intra-hippocampal injection of Aß1-42). We found that in Aß-affected brain, number of CD133+ cells was elevated after spatial training in the Morris water maze. The number of PSA-NCAM+ neuroblasts diminished by Aß injection was completely restored by subsequent spatial learning. Spatial training leads to elevated expression of NLRP3 inflammasomes in the SGZ (subgranular zones): CD133+ and PSA-NCAM+ cells started to express NLRP3 in sham-operated, but not AD rats. Taken together, our data suggest that expression of NLRP3 inflammasomes in CD133+ and PSA-NCAM+ cells may contribute to stimulation of adult neurogenesis in physiological conditions, whereas Alzheimer's type neurodegeneration abolishes stimuli-induced overexpression of NLRP3 within the SGZ neurogenic niche.

Organized Structure of Ventricular Fibrillation during Prolonged Heart Perfusion in Dogs.

The aim of the study was to identify the organized ventricular fibrillation (VF) activity in the dog heart and characterize its quantitative parameters during prolonged heart perfusion. MATERIALS AND METHODS: A total of four experiments on isolated dog's hearts perfused with the blood of a supporting dog were performed. Episodes of VF were recorded in the form of an electrogram followed by a spectral analysis by the fast Fourier transform in the range of 0.5-15 Hz. The frequency, spectral power (amplitude), and relative weight (%) of the 1st, 2nd, and 3rd highest amplitude oscillations were determined (frequency - mode; amplitude, relative weight - M±SEM; n=120). RESULTS: In the perfused dog heart, VF was characterized by an organized activity, as evidenced by the dominant structure of the oscillation frequencies. Oscillations with a frequency of 9-10 Hz (occurring in 1/10 of the 0.5-15 Hz range) represent 42-44% of the spectral power and dominate the structure of the oscillation frequencies. The frequency and spectral power of the dominating oscillations proved to be stable thus indicating that under perfusion, VF did not cause disturbances in the heart organized activity. CONCLUSION: Our experimentation with isolated perfused hearts revealed the patterns of VF that could not be revealed in situ under conditions complicated by nerve factors and ischemia in VF. The results of the work are protected with a patent which is applicable for VF diagnosis in implantable defibrillators.

Evolution of Oxygen-Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore-Fluorite Phase Boundary.

Sm2-xCaxZr2O7-x/2 (x = 0, 0.05, 0.1) and Gd2-xCaxZr2O7-x/2 (x = 0.05, 0.1) mixed oxides in a pyrochlore-fluorite morphotropic phase region were prepared via the mechanical activation of oxide mixtures, followed by annealing at 1600 °C. The structure of the solid solutions was studied by X-ray diffraction and refined by the Rietveld method, water content was determined by thermogravimetry (TG), their bulk and grain-boundary conductivity was determined by impedance spectroscopy in dry and wet air (100-900 °C), and their total conductivity was measured as a function of oxygen partial pressure in the temperature range: 700-950 °C. The Sm2-xCaxZr2O7-x/2 (x = 0.05, 0.1) pyrochlore solid solutions, lying near the morphotropic phase boundary, have proton conductivity contribution both in the grain bulk and on grain boundaries below 600 °C, and pure oxygen-ion conductivity above 700 °C. The 500 °C proton conductivity contribution of Sm2-xCaxZr2O7-x/2 (x = 0.05, 0.1) is ~ 1 × 10-4 S/cm. The fluorite-like Gd2-xCaxZr2O7-x/2 (x = 0.1) solid solution has oxygen-ion bulk conductivity in entire temperature range studied, whereas proton transport contributes to its grain-boundary conductivity below 700 °C. As a result, of the morphotropic phase transition from pyrochlore Sm2-xCaxZr2O7-x/2 (x = 0.05, 0.1) to fluorite-like Gd2-xCaxZr2O7-x/2 (x = 0.05, 0.1), the bulk proton conductivity disappears and oxygen-ion conductivity decreases. The loss of bulk proton conductivity of Gd2-xCaxZr2O7-x/2 (x = 0.05, 0.1) can be associated with the fluorite structure formation. It is important to note that the degree of Ca substitution in such solid solutions (Ln2-xCax)Zr2O7-δ (Ln = Sm, Gd) is low, x < 0.1. In both series, grain-boundary conductivity usually exceeds bulk conductivity. The high grain-boundary proton conductivity of Ln2-xCaxZr2O7-x/2 (Ln = Sm, Gd; x = 0.1) is attributable to the formation of an intergranular CaZrO3-based cubic perovskite phase doped with Sm or Gd in Zr sublattice.

[Age-related factors in the impact of chemical peeling with retinol on the functional parameters of the skin.]

Retinoids continue to be the main mean for the treatment of photoaging as they are able to align not only the various wrinkles but also to reduce skin pigmentation. Retinol serves as a reserve turned into an active substance by the cell itself in the required amount that triggers the expression of genes responsible for the development of epithelial tissue. The aim of the research therefore was to study the dynamics of the functional parameters of the skin after peeling with retinol in different age groups. 58 patients who had been treating with chemical peeling with retinol were under observation. All the patients were divided into two groups by age: the 1st group - 29 women from 30 to 45 years (38,51±4,34 years), the 2nd group - 29 women from 46 to 60 years (52,97±5,34 years). We studied the moisture content, acid-base balance, pigmentation, erythema degree, skin salinity and elasticity before treatment, 14 and 28 days after peeling. It was found that peeling with retinol bleached the skin better in the patients of the older age group, although their skin was more sensitive to the components of peeling. In the study of elasticity in the older age group, peeling with retinol reduced the extensibility, significantly increased the tone, viscosity and improved the total elasticity of the skin. Chemical peeling with retinol had the best effect on the skin in patients 46-60 years.

Proton and oxygen ion conductivity in the pyrochlore/fluorite family of Ln2-xCaxScMO7-δ (Ln = La, Sm, Ho, Yb; M = Nb, Ta; x = 0, 0.05, 0.1) niobates and tantalates.

The tolerance factor is a good criterion to understand the structural transitions in Ln2-xCaxScMO7-δ (Ln = La, Sm, Ho, Yb; M = Nb, Ta; x = 0, 0.05, 0.1). Decreasing the Ln ionic radius in Ln2ScNb(Ta)O7 leads to a morphotropic transition from a pyrochlore to a fluorite-like structure. Ca2+-doping leads to a pyrochlore-to-fluorite transition in Ln2-xCaxScMO7-δ (Ln = La, Sm) and a fluorite-to-pyrochlore transition in Ho2-xCaxScNbO7-δ. Proton contribution to the total conductivity was observed for Ln2-xCaxScNb(Ta)O7-δ (Ln = La, Sm; x = 0, 0.05, 0.1) 3+/5+ pyrochlores and the maximum proton contribution was shown by Sm1.9Ca0.1ScMO6.95 (M = Nb, Ta), which are located at the boundary between pyrochlores and fluorites (comparative study of electrical conduction and oxygen diffusion). Proton conduction of Sm1.9Ca0.1ScNbO6.95 and Sm1.9Ca0.1ScTaO6.95 pyrochlores persists up to 800 and 850 °C, respectively. The conductivity of fluorite-like Ho2-xCaxScNbO7-δ (x = 0, 0.05) and Yb2ScNbO7 is dominated by the oxygen ion transport, in accordance with their energy activation values 1.09-1.19 eV. The dielectric permittivity and TG studies were used for the investigation of oxygen vacancy dynamics and water incorporation into the Ln2-xCaxScNb(Ta)O7-δ (Ln = La, Sm, Ho, Yb; x = 0, 0.05, 0.1) lattice. It is shown that oxygen vacancy-related dielectric relaxation in the range of 550-650 °C (ambient air), typical of pyrochlores and fluorites with pure oxygen ion conductivity, decreases and disappears for proton-conducting oxides.

[Development and preclinical studies of insulating membranes based on poly-3-hydroxybutyrate-co-3-hydroxyvalerate for guided bone regeneration].

Bone tissue damages are one of the dominant causes of temporary disability and developmental disability. Currently, there are some methods of guided bone regeneration employing different osteoplastic materials and insulation membranes used in surgery. In this study, we have developed a method of preparation of porous membranes from the biopolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), produced by a strain of Azotobacter chroococcum 7B. The biocompatibility of the porous membranes was investigated in vitro using mesenchymal stem cells (MSCs) and in vivo on laboratory animals. The cytotoxicity test showed the possibility of cell attachment on membrane and histological studies confirmed good insulating properties the material. The data obtained demonstrate the high biocompatibility and the potential application of insulating membranes based on PHBV in bone tissue engineering.

Culturing of Mouse Mesenchymal Stem Cells on Poly-3-Hydroxybutyrate Scaffolds.

We studied the possibility of long-term culturing of mouse mesenchymal stem cells on a porous scaffold made of biocompatible polymer poly-3-hydroxybutyrate. The cells remained viable for at least 2 months and passed more than 65 population doublings in culture. Culturing on the scaffold did not change surface phenotype of cells. 3D poly-3-hydroxybutyrate scaffolds are appropriate substrate for long-term culturing of mesenchymal stem cells.

[Hplc estimation of coenzyme Q(10) redox status in plasma after intravenous coenzyme Q(10) administration].

The pharmacokinetics of the total pool of coenzyme Q(10) (Co(10)), its oxidized (ubiquinone) and reduced (ubiquinol, CoQ(10)H2) forms have been investigated in rats plasma during 48 h after a single intravenous injection of a solution of solubilized CoQ(10) (10 mg/kg) to rats. Plasma levels of CoQ(10) were determined by HPLC with spectrophotometric and coulometric detection. In plasma samples taken during the first minutes after the CoQ(10) intravenous injection, the total pool of coenzyme Q(10) and proportion of CoQ(10)H2 remained unchanged during two weeks of storage at -20°C. The kinetic curve of the total pool of coenzyme Q(10) corresponds to a one-part model (R² = 0.9932), while the corresponding curve of its oxidized form fits to the two-part model. During the first minutes after the injection a significant portion of plasma ubiquinone undergoes reduction, and after 7 h the concentration of ubiquinol predominates. The decrease in the total plasma coenzyme Q(10) content was accompanied by the gradual increase in plasma ubiquinol, which represented about 90% of total plasma CoQ(10) by the end of the first day. The results of this study demonstrate the ability of the organism to transform high concentrations of the oxidized form of CoQ(10) into the effective antioxidant (reduced) form and justify prospects of the development of parenteral dosage forms of CoQ(10) for the use in the treatment of acute pathological conditions.

[Intravenous injection of coenzyme Q10 increases its level in rat brain].

It is established that intravenous injection of solubilized coenzyme Q10 provides quick and lasting increase in its level in the brain as compared to control intact rats and those with cerebral ischemia. These new data provide a basis for studying the efficacy of coenzyme Q10 as a neuroprotective agent in ischemic stroke.

[Diagnostics of acute adhesive intestinal obstruction by the method of measuring intra-abdominal pressure].

Questions of diagnostics of acute adhesive intestinal obstruction (AIO) including erased picture of the disease are considered. The data of 120 patients with acute intestinal obstruction are presented in whom the intra-abdominal pressure (IAP) was investigated in dynamics. The questions of degree of IAP in acute intestinal obstruction of different genesis and with different levels of disturbed patency of the gastro-intestinal tract are discussed. The radiological data are compared with the parameters of IAP in acute intestinal obstruction. The algorithm of strategy of treatment of patients with acute intestinal obstruction based on the size of IAP is proposed.

[Antibacterial activity of nanostructured silver gel].

AIM: Evaluation of antimicrobial activity of L-cysteine silver gel against various species of pathogenic and opportunistic microorganisms. MATERIALS AND METHODS: Antibacterial activity of L-cysteine silvergel with silver concentration from 1.28 x 10(-3) to 3.75 x10(-3) mole/l was studied by using agar diffusion test. Reparation processes were determined experimentally in 102 male Wistar rats (150 g) by forming under ether anesthesia a 225 mm2 skin wound on the back surface of the body and by introducing virulent strain Staphylococcus aureus 236 24-hour suspension (10(6) CFU/ml) inside the wound. The rat wounds were treated with L-cysteine silver gel once per day for one week and proliferation processes were studied on day 7, 14 and 21. RESULTS: Antibacterial activity of L-cysteine silver gel was detected against test strains: S. aureus ATCC 25923; Bacillus subtilis 537; Escherichia coli ATCC 25922; Shigella sonnei 1908; Pseudomonas aeruginosa ATCC 27853; Salmonella typhimurium 5715 and Candida albicans ATCC 885-653. Mean period of wound healing was reduced by 3 days when L-cysteine silver gel was used, index of healing acceleration was approximately 20%. CONCLUSION: L-cysteine silver gel has antibacterial and wound healing properties, it can be used for the creation of new medical preparations.

[Comparison of different ELISAs for detection of antibodies to swine vesicular disease virus in sera from experimentally infected animals].

The study has shown the efficiency of a competitive ELISA (C-ELISA) variant or an indirect ELISA (I-ELUSA) in the detection of antibodies to swine vesicular disease virus (SVDV) versus traditional assays, such as a microneutralization test, a blocking ELIDA test, and a the reference test Ceditest SVDV (Cedi-Diagnostics B.V., Netherlands). Specific antibodies in the pig sera could be detected by C-ELISA on days 4-5 and by I-ELISA on day 6 after experimental SVDV infection. Specific antibodies were detected in a contact pig 11 days after the beginning of the experiment.

[Cytological evaluation of laser therapy influence upon skin reparation].

Evidence on the studying of the effectiveness the low intensive laser radiation influence as complex treatment of patient with maxillofacial phlegmons with using of the cytological method were presented. Results of the laser therapeutist were in acceleration of the inflammation stage. The neutrophil granulocytes and macrophages settled down in wound earlier then in the control. This led to acceleration of the wound healing.

Phase transition in single crystal Cs2Nb4O11.

We studied temperature dependence of complex capacitance, impedance, and polarized Raman spectra of single crystal Cs2Nb4O11. First, we observed a sharp lambda-shaped peak at 165 degrees C in the complex capacitance, then found drastic changes in the Raman spectra in the same temperature range. Utilizing the pseudosymmetry search of structure space group, we attributed the observed anomalies to a structural change from the room temperature orthorhombic Pnn2 to another orthorhombic Imm2. We also measured room temperature polarized Raman spectra in different symmetries of normal vibrations and assigned high wavenumber Raman bands to the internal vibrations of NbO6 octahedra and NbO4 tetrahedra.