[Changes in the type and amount of bone collagens in chronic suppurative otitis media]. / Izmenenie tipovogo i kolichestvennogo sootnosheniya kollagenov kostnoi tkani pri khronicheskom gnoinom srednem otite.

OBJECTIVE: Comparative assessment of the collagen-tissue interaction in the bone tissue of the middle ear structures in patients with chronic suppurative otitis media (CSOM). MATERIAL AND METHODS: A prospective study of 42 patients aged 16-60 years with CSOM admitted for reconstructive sanitizing surgery was performed. To study the collagen-tissue interaction, intraoperative samples of the bone tissue of the middle ear were used. A software calculation of vascular-stromal areas and ratios of various types of bone tissue collagen was carried out during histomorphological examination. RESULTS AND DISCUSSION: The quantitative and qualitative parameters of bone tissue collagen obtained intraoperatively in patients with CSOM were studied. The cavities of the middle ear are in the phase of a chronic purulent process, when the bone structures are morphologically disorganized according to the pathological type, and sclerosis with overgrowth of the cellular structure of the mastoid process is considered a favorable outcome for delimiting the focus of inflammation in the pyramid of the temporal bone. CONCLUSIONS: Changes in the processes of collagen remodeling of bone structures contribute to the maintenance of inflammation of the middle ear in all clinical forms of CSOM. Pathological osteogenesis can serve as an indicator of the progressive course of a purulent-destructive process in the cavities of the middle ear, which makes it possible to reliably determine the rate of bone tissue transformation to predict relapse after reconstructive and sanitizing surgery.

Modification of a spectrophotometric method for assessment of monoamine oxidase activity with 2,4-dinitrophenylhydrazine as a derivatizing reagent.

The aim of the study was to modify a simple and widely used spectrophotometric assay for MAO activity evaluation with 2,4-dinitrophenylhydrazine. A modified procedure includes molar absorption coefficients of 2,4-DNP-hydrazone benzaldehyde and 2,4-DNP-hydrazone 5-hydroxyindolylacetaldehyde as 2.3 × 104mol-1l cm-1 and 1.0 × 104 mol-1l cm-1, respectively. Such an approach allows to express specific enzyme activity as nmol product formed/min/mg protein.

Low-Voltage Domain-Wall LiNbO3 Memristors.

Application of conducting ferroelectric domain walls (DWs) as functional elements may facilitate development of conceptually new resistive switching devices. In a conventional approach, several orders of magnitude change in resistance can be achieved by controlling the DW density using supercoercive voltage. However, a deleterious characteristic of this approach is high-energy cost of polarization reversal due to high leakage current. Here, we demonstrate a new approach based on tuning the conductivity of DWs themselves rather than on domain rearrangement. Using LiNbO3 capacitors with graphene, we show that resistance of a device set to a polydomain state can be continuously tuned by application of subcoercive voltage. The tuning mechanism is based on the reversible transition between the conducting and insulating states of DWs. The developed approach allows an energy-efficient control of resistance without the need for domain structure modification. The developed memristive devices are promising for multilevel memories and neuromorphic computing applications.

Inkjet printable-photoactive all inorganic perovskite films with long effective photocarrier lifetimes.

Photoactive perovskite quantum dot films, deposited via an inkjet printer, have been characterized by x-ray diffraction and x-ray photoelectron spectroscopy. The crystal structure and bonding environment are consistent with CsPbBr3 perovskite quantum dots. The current-voltage (I-V) and capacitance-voltage (C-V) transport measurements indicate that the photo-carrier drift lifetime can exceed 1 ms for some printed perovskite films. This far exceeds the dark drift carrier lifetime, which is below 50 ns. The printed films show a photocarrier density 109 greater than the dark carrier density, making these printed films ideal candidates for application in photodetectors. The successful printing of photoactive-perovskite quantum dot films of CsPbBr3, indicates that the rapid prototyping of various perovskite inks and multilayers is realizable.

Effect of Repeated 1-h Episodes of Immobilization Stress on Activity of Glucocorticoid Metabolism Enzymes in the Liver.

Differences in corticosterone level associated with different activity of glucocorticoid-oxidizing enzymes in the liver were revealed in rats exposed to stress. Pro-inflammatory changes in the liver were associated with enhanced CYP3A-dependent monooxygenation.

Activity of Heme Synthesis Enzymes in the Bone Marrow and Liver of August and Wistar Rats During the Neonatal Period and After Acute Postnatal Hypoxia.

Activity of heme synthesis enzymes in newborn August and Wistar rats was studied after acute hypoxic hypoxia. Daily production of erythrocytes and activities of aminolevulinate synthase, aminolevulinate dehydratase, and heme synthetase were measured in the bone marrow (15-30 min after birth and on days 1 and 3 of life) and liver (day 3 after birth). Hypoxia was followed by a decrease in activity of heme synthesis enzymes in the liver (especially in August rats) and reduction of the daily erythrocyte production (especially in Wistar rats). Our results suggest that the response of heme synthesis enzymes to hypoxic exposure in newborn rats is genetically determined. The observed changes are more pronounced in Wistar rats.

Glucocorticoid-Related Regulation of LPO in Brain Cortex during Anxiogenic Stress.

Under conditions of periodic exposures to anxiogenic stress, intensification of LPO in the brain cortex is a glucocorticoid-dependent process. Glucocorticoid receptor antagonist RU38486 prevented increase in monoamine oxidase B activity and content of LPO products of in brain cortex typical of anxiogenic stress. Normalization of LPO intensity under the effect of glucocorticoid receptor antagonist was associated with the correction of stress-induced disturbances.

Transformation of catalytic characteristics of cerebral monoamine oxidases in experimental posttraumatic stress disorders.

We studied the contribution of the transformation of the catalytic properties of cerebral monoamine oxidase in the development of behavioral disorders during stress. Monoamine oxidase activities and catalytic characteristics, LPO intensity, and oxidative modification of proteins in suspension of the brain mitochondria were evaluated over the course of experimental posttraumatic stress disorder. The detected shifts were comparable with the results of neuroethologic testing. The development of behavioral disorders presented by low exploratory activity and high anxiety was associated with transformation of catalytic characteristics of cerebral monoamine oxidases, associated with the development of oxidative stress with predominant intensification of metal-catalyzed protein oxidation.

Ferroelectric tunnel junctions with graphene electrodes.

Polarization-driven resistive switching in ferroelectric tunnel junctions (FTJs)--structures composed of two electrodes separated by an ultrathin ferroelectric barrier--offers new physics and materials functionalities, as well as exciting opportunities for the next generation of non-volatile memories and logic devices. Performance of FTJs is highly sensitive to the electrical boundary conditions, which can be controlled by electrode material and/or interface engineering. Here, we demonstrate the use of graphene as electrodes in FTJs that allows control of interface properties for significant enhancement of device performance. Ferroelectric polarization stability and resistive switching are strongly affected by a molecular layer at the graphene/BaTiO3 interface. For the FTJ with the interfacial ammonia layer we find an enhanced tunnelling electroresistance (TER) effect of 6 × 10(5)%. The obtained results demonstrate a new approach based on using graphene electrodes for interface-facilitated polarization stability and enhancement of the TER effect, which can be exploited in the FTJ-based devices.

Lipid peroxidation and state of the erythron in newborn rats under normal conditions and impairment of sensorimotor reflexes.

Specimens with a stereotypic sensorimotor deficit were revealed among newborn rats due to abnormalities in prenatal ontogeny and birth stress. Genetically determined differences in the total lipid content of blood plasma were found in Wistar and August rat pups. Hence, LPO processes were shown to differ in these animals. August rats with intense lipid metabolism were characterized by higher activity of LPO in comparison with Wistar rats. The increase in LPO was associated with a relatively low activity of antioxidant enzymes. Impairment of sensorimotor reflexes in newborn Wistar and August rats was accompanied by suppression of the erythron and activation of extravascular hemolysis.

Effects of glucocorticoid antagonist on protein carbonylation in rat liver after daily 1-hour immobilizations.

Daily (for 3 days) 1-hour immobilizations were followed by an increase in protein oxidative modification and leukocyte infiltration in the liver, and a decrease in monoamine oxidase B activity. Receptor antagonist of glucocorticoids RU38486 limited the stress-induced increase in protein carbonylation and decrease in monoamine oxidase B activity in the organ and enhanced leukocyte infiltration of the liver.

Correlation between circulating corticosterone and protein carbonylation in the liver after short-term hypokinesia.

We studied the correlation of the concentration of circulating corticosterone and parameters of dexamethasone suppression test with the level of protein carbonylation in the liver after short-term hypokinesia. Increasing hypokinesia duration was followed by worsening of disturbances in the hypothalamic-pituitary-adrenal system via a negative feedback mechanism and enhanced protein carbonylation in the liver.

[The energetic metabolism in newborns in normal conditions and under development of disorders of adaptation in early postnatal period].

The article deals with the prospective complex approach to laboratory analysis of energetic metabolism under states of newborns. The approach provides simultaneous detection of content of main energy substrates, activity of adenosinetriphosphatases and succinate dehydrogenases in umbilical blood, characterized by high sensitivity to hypoxia.

[Cortisol levels in cord blood with various violations of neonatal adaptation].

Shifting extra uterine existence is a serious test of maturity of all functional systems of the newborn, so in recent years, the more attention is payed for the adaptation of the newborn. It is known that the pathological course of pregnancy is a violation of the functional state of the adrenal cortex, and prolonged exposure of the pathological factor leads to the inhibition of adrenocortical function and a decrease of the adaptive capabilities of a newborn. Therefore, serum cortisol levels could be a predictor of complications in preterm infants. Based on this, it seems appropriate to study changes in the content of serum cortisol cord blood prior to the development of various syndromes neonatal maladjustment. The clinical and laboratory examination of term infants with various disorders of adaptation: regurgitation, pain, hyperexcitability , depression, cardio-respiratory depression, bleeding in the skin, toxic erythema. It is shown that the most prominent violations maladjustment processes occur on the background of decreased cortisol. Border states, which are formed on the background of normal or elevated cortisol, are not accompanied by significant impairments of adaptation processes. On the basis of the data was drawn a conclusion about the possibility of using changes of cortisol in cord blood as a reliable indicator of neonatal adaptation processes, pointing to the possibility of the development of pathological conditions.

[Condition of erythron in newbord rats with disturbed sensorimotor reflexes].

Early adaptation issues of newborn rats of Wistar population and August line were examined. Absence of the connection between the condition of a female during the pregnancy and the birth, and newborn rats in early postnatal period was revealed.

[Immunosupressive effect of hypokinetic stress and sensitization of thymus to glucocorticoids].

24-hour hypokinetic stress expressed in decrease of sensitivity of cellular and humoral immu nity to subsequent immunization with sheep erythrocytes was studied. The development of this phenomenon is associated with sensitization of lymphoid tissue to hypoplasia effect of glycocorticoid hormones. In introduction of glycocorticoid stress, the animals revealed a more pronounced depression of proliferative activity of thymocytes compared with non stressed animals.

[The activity of platelet monoamine oxidase, red blood cell Mg-ATPase, and the level of serum magnesium in the acute period of adaptation in neonatal infants].

For early diagnosis of neonatal transient conditions that may become abnormal, it is promising to apply an integrative approach comprising the concurrent definition of the indices characterized by a high sensitivity to hypoxia. This study has investigated the predictive value of platelet monoamine oxidase and red blood cell Mg-ATPase in neonatal infants.

[Effect of early postnatal hypoxia on Wistar and August rats].

It was proved that hypoxia tolerance often goes together with forming of oxidative stress tolerance and has genetic predetermination on hypoxic influence. Interline difference ofhypoxia sensitivity is mainly defined by difference of oxygen-transport systems state. Genetically predetermined differences between investigated lines give the August rats the ability to use mechanisms of resistant strategy more effectively, and the Wistar rats--to use tolerant strategy more effectively.

[Influence repeated stress on immune responciveness and monooxigenase activity of normotensive and hypertensive rats].

Repeated stress led to antipodal directions in immune system and cytochrome P450 activities of normotensive and hypertensive rats. Enhancement of the Reaction of Delayed Hypersensitivity, suppression of cytochrome P450-mediated monooxigenase activities were observed in Wistar rats. On the contrary, in the NISAG decrease of the Reaction Delayed Hypersensitivity, elevation of cytochrome P450-mediated monooxigenase activities were observed, as comparison with Wistar rats.

[Influence of repeated stress exposures with hypoxia intolerance on rats oxidized proteins and lipoperoxidation shifts].

Rarely repeated episodes of immobilization stress led to misbalance between pro oxidant and antioxidant systems. So in the brain, kidneys, spleen we observed elevation of oxidized proteins level. In contrast, in the thymus and bone marrow the protein carbonilation was attenuated. In the liver, oxidized protein level remained unchanged. Simultaneously the level of liver lipoperoxidation was increased. These shifts were accompanied with attenuation of catalase activity in the liver and elevation of xanthine oxidase activity in the spleen and erythrocytes.