Experimental Models for Studying Structural and Functional State of the Pathological Liver (Review).

Liver pathologies remain one of the leading causes of mortality worldwide. Despite a high prevalence of liver diseases, the possibilities of diagnosing, prognosing, and treating non-alcoholic and alcoholic liver diseases still have a number of limitations and require the development of new methods and approaches. In laboratory studies, various models are used to reconstitute the pathological conditions of the liver, including cell cultures, spheroids, organoids, microfluidic systems, tissue slices. We reviewed the most commonly used in vivo, in vitro, and ex vivo models for studying non-alcoholic fatty liver disease and alcoholic liver disease, toxic liver injury, and fibrosis, described their advantages, limitations, and prospects for use. Great emphasis was placed on the mechanisms of development of pathological conditions in each model, as well as the assessment of the possibility of reconstructing various key aspects of pathogenesis for all these pathologies. There is currently no consensus on the choice of the most adequate model for studying liver pathology. The choice of a certain effective research model is determined by the specific purpose and objectives of the experiment.

Lanthanoid-doped quaternary garnets as phosphors for high brightness cathodoluminescence-based light sources.

Gadolinium-yttrium- aluminum-gallium garnets (GYAGG) doped and codoped with Eu, Tb, and Ce were manufactured as ceramics to develop long-wavelength phosphors for high-brightness white light sources based on cathodoluminescence (CL). The CL light yield (LY) of Tb-doped ceramics at high-intensity electron beam excitation is shown to be more than twice as high as that of the conventional phosphor YAG:Ce, whereas codoping with Eu to redshift the chromaticity results in reducing the LY approximately to the level of YAG:Ce. The LY might be substantially improved by using a mix of Tb- and Eu-doped GYGAG powders instead of a single codoped GYGAG to produce ceramic phosphor. The high LY is explained by favorable contribution of Gd sublattice in excitation transfer to activator ions. Chromaticity of phosphors GYGAG:Tb, Eu can be tuned in a wide range by varying the ratio of Tb to Eu concentration. They are radiation resistant and stabile in the temperature range from 300 to 450 K.

Modern Approaches to Testing Drug Sensitivity of Patients' Tumors (Review).

Drug therapy is still one of the basic techniques used to treat cancers of different etiology. However, tumor resistance to drugs is a pressing problem limiting drug treatment efficacy. It is obvious for both modern fundamental and clinical oncology that there is the need for an individual approach to treating cancer taking into account the biological properties of a tumor when prescribing chemo- and targeted therapy. One of the promising strategies is to increase the antitumor therapy efficacy by developing predictive tests, which enable to evaluate the sensitivity of a particular tumor to a specific drug or a drug combination before the treatment initiation and, thus, make individual therapy selection possible. The present review considers the main approaches to drug sensitivity assessment of patients' tumors: molecular genetic profiling of tumor cells, and direct efficiency testing of the drugs on tumor cells isolated from surgical or biopsy material. There were analyzed the key directions in research and clinical studies such as: the search for predictive molecular markers, the development of methods to maintain tumor cells or tissue sections viable, i.e. in a condition maximum close to their physiological state, the development of high throughput systems to assess therapy efficiency. Special attention was given to a patient-centered approach to drug therapy in colorectal cancer.

Multiphoton Microscopy and Mass Spectrometry for Revealing Metabolic Heterogeneity of Hepatocytes in vivo.

The aim of the investigation was to study the possibility of revealing the heterogeneity of normal liver hepatocytes in terms of metabolic status using the modern methods of multiphoton microscopy and mass spectrometry. Materials and Methods: Heterogeneity of hepatocytes in terms of total metabolic activity was assessed using multiphoton microscopy based on the autofluorescence intensity of intracellular cofactors NAD(P)H and FAD. Hepatocyte heterogeneity in terms of intensity of intracellular metabolic processes was determined using the fluorescence lifetime imaging (FLIM) method based on the data about fluorescence lifetime contributions of various forms of NAD(P)H. The method of time-of-flight secondary ion mass spectrometry (TоF-SIMS) was used to study the lipid and amino acid composition of hepatocytes. Results: It has been revealed using multiphoton microscopy that hepatocytes are heterogeneous in terms of general metabolic activity. Using FLIM, it was established that the heterogeneity degree was high in terms of intensity of oxidative phosphorylation, glycolysis, and synthetic processes (lipogenesis, nucleic acid synthesis, and the pentose phosphate pathway). The TоF-SIMS method revealed the presence of hepatocyte heterogeneity in terms of amino acid and lipid composition, which points to various intensities of synthetic processes in individual hepatocytes. Moreover, differences in the content of PO3 ions were revealed. The results of ToF-SIMS study correlate with the data obtained by multiphoton microscopy and FLIM, confirming the revealed heterogeneity of hepatocytes in terms of general metabolic activity and intensity of intercellular metabolic processes. Conclusion: The latest methods of fluorescence bioimaging and mass spectrometry proved to be effective in revealing hepatocyte heterogeneity in terms of metabolic status. The presence of heterogeneity should be taken into account in studying the liver tissue under various conditions with the application of fluorescence bioimaging methods.

[Pharmacological correction of total venous reflux in patients with varicose veins]. / Farmakologicheskaia korrektsiia summarnogo venoznogo refliuksa u bol'nykh s varikoznoi bolezn'iu.

AIM: To evaluate the efficacy of a micronized purified flavonoid fraction in patients with primary venous disease. The study enrolled 31 patients, with varicose veins observed in a total of 47 lower extremities which were divided into 3 groups depending on the CEAP clinical class. The group of class C2 included 19 limbs, with the groups of C3 and C4 comprising 14 limbs each. The patients received a micronized purified flavonoid fraction (Detralex) in a daily dose of 1000 mg for 1 month. The venous function of the lower extremities was examined using venous photoplethysmography before and after the course of pharmacotherapy. Venous refilling time and venous half-refilling time were measured as indicators of total venous reflux. In the overall sample of patients with clinical class C2-C4, a significant increase in venous photoplethysmography parameters was found after the course of administration of the micronized purified flavonoid fraction. Thus, the venous refilling time increased from 15.5 (11; 19) s to 19.3 (13; 25) s, the venous half-refilling time increased from 6.5 (5; 7) s to 7.5 (5; 9) s. At the same time, in the group of patients with clinical class C2 and C3, a significant increase in the venous refilling time was found, and in patients with C4, the increase was not significant. There was an inverse correlation between the increase in venous refilling time after drug exposure and the clinical class of venous insufficiency according to the CEAP, as well as the patient's age. Thus, the administration of the micronized purified flavonoid fraction for 1 month in primary venous disease led to a decrease in the total venous reflux. The effect of the micronized purified flavonoid fraction on the total venous reflux was higher in younger patients and in patients with a lower clinical class of the disease.

[Etiopathogenetic factors of wound healing in chronic post-intubation cicatricial stenosis of the larynx and trachea]. / Etiopatogeneticheskie faktory zazhivleniya rany pri khronicheskikh postintubatsionnykh rubtsovykh stenozakh gortani i trakhei.

Despite the existing modern high-tech methods of examination and a variety of surgical treatment methods, the problem of diagnosis, treatment and rehabilitation of patients with chronic post-intubation cicatricial stenosis of the larynx and trachea still requires further study. Improving the understanding and correction of cellular, molecular genetic and biochemical disorders in a chronic wound is a key condition for increasing the efficiency of diagnosis, individual prognosis of the clinical course and the conduct of adequate therapeutic and preventive measures for post-intubation cicatricial laryngotracheal stenoses. In this regard, it seemed appropriate to analyze the existing etiopathogenetic factors of pathological wound healing in chronic post-intubation cicatricial stenosis of the larynx and trachea. Our attempt to summarize the available literature data demonstrated that laryngotracheal scars are a fibro-proliferative disease caused by aberrant wound healing after a damaging effect on the tissues of the larynx and trachea. The article describes the most pathogenetically significant healing, repair, and scarring factors in post-intubation laryngotracheal stenoses, including transforming growth factor ß1, vascular growth factor A, type I and III collagen, and matrix metalloproteinases. An assessment of the features of the diagnostic and prognostic significance of these markers will increase the effectiveness of the treatment of patients with chronic cicatricial stenosis of the larynx and trachea, and will also serve as a prerequisite for the development of strategies for diagnostic, treatment, prophylactic and rehabilitation measures that will improve the quality of medical care and the quality of life of patients with chronic cicatricial stenosis of the larynx and trachea.

2D/3D buccal epithelial cell self-assembling as a tool for cell phenotype maintenance and fabrication of multilayered epithelial linings in vitro.

Maintaining the epithelial status of cells in vitro and fabrication of a multilayered epithelial lining is one of the key problems in the therapy using cell technologies. When cultured in a monolayer, epithelial cells change their phenotype from epithelial to epithelial-mesenchymal or mesenchymal that makes it difficult to obtain a sufficient number of cells in a 2D culture and to use them in tissue engineering. Here, using buccal epithelial cells from the oral mucosa, we developed a novel approach to recover and maintain the stable cell phenotype and form a multilayered epithelial lining in vitro via the 2D/3D cell self-assembling. Transitioning the cells from the monolayer to non-adhesive 3D culture conditions led to formation of self-assembling spheroids, with restoration of their epithelial characteristics after epithelial-mesenchymal transition. In 7 days, the cells within spheroids restored the apical-basal polarity, and the formation of both tight (ZO1) and adherent (E-cadherin) intercellular junctions was shown. Thus, culturing buccal epithelial cells in a 3D system allowed us to recover and durably maintain the morphological and functional characteristics of epithelial cells. The multilayered epithelial lining formation was achieved after placing spheroids for 7 days onto a hybrid matrix, which consisted of collagen layers and reinforcing poly (lactide-co-glycolide) fibers and was proven promising for replacement of the urothelium. Thus, we offer an effective technique of forming multilayered epithelial linings on carrier-matrices using cell spheroids that was not previously described elsewhere and can find a wide range of applications in tissue engineering, replacement surgery, and regenerative medicine.

[The clinical diagnostic significance of auto antibodies to CD74 at axial spondylarthritis.]

The modern diagnostic approaches permit to diagnose axial spondylarthrosis (axSpA) at roentgenologic stage corresponding to ankylosing spondylitis (AS). While early diagnostic of non-roentgenologic axSpA (nr-axSpA) is still complicated. This situation conditions a need in searching new laboratory biomarkers for early diagnostic of spondylarthrosis, including auto-antibodies to antigen CD74 described recently. The purpose of study is to evaluate clinical diagnostic significance of auto-antibodies to antigen CD74 in case of axSpA. The technique of quantitative enzyme-linked immunosorbent assay was applied to measure content of auto-antibodies IgA to CD74 in samples of serum from 140 patients with axSpA: 68 with AS, 46 with nr-axSpA, 26 with psoriatic arthritis (PA) and 37 healthy representatives of control group with signs of axSpA totally clinically excluded. The average values of concentration of auto-antibodies IgA to CD74 in patients with axSpA and nr-axSpA made up to 3,5 ± 3,0 and 3,8 ± 2,9 U/ml correspondingly that reliably and significantly differed from patients with PA and healthy individuals - 2,1 ± 1,4 and 1,3 ± 1,4 U/ml correspondingly (p < 0,05). At threshold value of content of auto-antibodies IgA to CD74 higher than 2.0 U/ml in case of axSpA diagnostic sensitivity made up to 64.4%, specificity - 89.2%, risk factor of positive result - 5.9 whereas in patients with nr-axSpA at concentration 1.7 U/ml - 73,1%, 84% and 4,5 correspondingly. The auto-antibodies IgA to antigen CD74 are associated withaxSpA but not with PA that permits to use the given marker for diagnostic of axial spondylarthrosis and also in case of differential diagnostic between axSpA and PA.

Surface micromorphology of cross-linked tetrafunctional polylactide scaffolds inducing vessel growth and bone formation.

In the presented study, we have developed a synthetic strategy allowing a gradual variation of a polylactide arms' length, which later influences the micromorphology of the scaffold surface, formed by a two-photon polymerization technique. It has been demonstrated that the highest number of cells is present on the scaffolds with the roughest surface made of the polylactide with longer arms (PLA760), and osteogenic differentiation of mesenchymal stem cells is most pronounced on such scaffolds. According to the results of biological testing, the PLA760 scaffolds were implanted into a created cranial defect in a mouse for an in vivo assessment of the bone tissue formation. The in vivo experiments have shown that, by week 10, deposition of calcium phosphate particles occurs in the scaffold at the defect site, as well as, the formation of a new bone and ingrowth of blood vessels from the surrounding tissues. These results demonstrate that the cross-linked microstructured tetrafunctional polylactide scaffolds are promising microstructures for bone regeneration in tissue engineering.

Abundance estimate of the Okhotsk Sea population of the bowhead whale (Balaena mysticetus Linnaeus, 1758).

Abundance of 388 ± 108 whales for the Okhotsk Sea bowhead whale population based on individual genotyping was estimated using the capture-recapture method for the open population model. The data demonstrate that this endangered population shows no signs of recovery.

Comparative Analysis of Proliferation and Viability of Multipotent Mesenchymal Stromal Cells in 3D Scaffolds with Different Architectonics.

3D biodegradable materials (scaffolds) containing bioactive hydroxyapatite molecules fabricated by foaming in supercritical carbon dioxide and by selective laser sintering were used for culturing of mesenchymal stromal cells from the human adipose tissue. Experiments showed that stromal cells from the human adipose tissue adhered and proliferated on all studied types of structures. Addition of hyproxyapatite to the scaffold stimulated proliferation of stromal adipose tissue cells.

[Influence of high altitude on the functional status and morbidity of teenagers].

With the aim to determine the influence of the high latitudes on the main indices of the blood and morbidity, physical development of adolescents of 14 years old residing in Kirov (n = 139) and Ukhta (n = 253), the evaluation of basic parameters of their blood, physical development and morbidity has been performed accordingly to standards methods. The inhabitancy of adolescents in high latitudes (Ukhta) in comparison with their peers from temperate latitudes (Kirov) leads to body weight gain of 4.7 kg in girls and 5.8 kg in boys, gives rise to the increase in gender diferences in hemoglobin concentrations and ESR and boosts overall morbidity.

[The response of cerebral blood flow and systemic arterial blood pressure to hypercapnia and hypocapnia in humans].

In 11 healthy volunteers 21 +/- 3.7 years old was monitored cerebral blood flow (CBF) by transcranial Doppler (TCD) of middle cerebral artery and mean hemodynamic arterial blood pressure (MAP) by continuous non-invasive measurement "beat-to-beat" at normocapnia, hypercapnia and hypocapnia. Hypercapnia was creating by rebreathing, hypocapnia was creating by spontaneous hyperventilation. The partial pressure of CO2 in alveolar air (PetCO2) was monitored by capnograph, embedded in the TCD-analyzer. During hypercapnia the velocity of CBF and PetCO2 were significantly increased already at 10 s, which was considerably earlier than the increase in the MAP (30 s). During hypocapnia velocity CBF and PetCO2 were significantly decreased at 10 s, and MAP was not changed. We have installed the threshold PetCO2 42 (41; 44) mm Hg, below which amplification CBF occurs at a constant MAP and reflects the true cerebrovascular reactivity to CO2.

[Impact of coal mining on bird distribution in Upper Angara Region].

Bird distribution in the first half of summer was analyzed in the areas of past and present opencast coal mining in the Upper Angara Region. Most species preferred forest habitats even with traces of industrial impact. Artificial water bodies introduced as a result of coal mining increase the diversity of bird species.