[Impaired expression of cell-cycle regulatory proteins in seborrheic keratosis]. / Narushenie ékspressii belkov-reguliatorov kletochnogo tsikla pri seboreinom keratoze.

Seborrheic keratosis (SK) is a benign skin tumor of unknown etiology and pathogenesis. Many details remain unclear despite that there have been a number of studies of cell-cycle abnormalities. AIM: to investigate the expression of the cell-cycle regulatory proteins p53 and p16 and the cell proliferation marker Ki-67 in SK. SUBJECTS AND METHODS: The investigation used intraoperative SK material obtained from 130 patients. Tumors were removed from UV-exposed parts of the body in 63 (48%) patients and from the places that were more often closed in 67 (51.5%). An immunohistochemical (IHC) study was performed using monoclonal antibodies to p53, p16, and Ki-67. RESULTS: A positive reaction with monoclonal antibodies to p53 was recorded in 66 (50.7%) SK samples. In 92.1% of cases, the expression of p53 was found in SK located at the sites that were most exposed to UV radiation (p=0.00001). A positive reaction with monoclonal antibodies to p16 was observed in all SK cases as cytoplasmic staining of more than 50% of the tumor cells: a strong staining in 63 SK samples (overexpression) and a weak staining in 67 SK ones. The level of p16 expression correlated with age (R=0.21; p=0.019) and SK location at the sites exposed to increased insolation (R=0.35; p=0.000038). Overexpressions of p53 and p16 were significantly more commonly recorded in irritated SK. The tumor proliferative activity by the level of Ki-67 expression was low (3.0 to 11.3%). The largest number (8.5±4.8%) of proliferating cells was recorded in irritated SK (p=0.0000001). CONCLUSION: The found disorders in the expression of cell-cycle regulatory proteins in SK are suggestive of tumor suppressor activation and keratinocyte senescence. There may be malignant tumor transformation in irritated SK in terms of the significant increase in the expression of p53, p16 in the presence of high cell proliferative activity.

ASSESSMENT OF THE LIPID PEROXIDE OXIDATION PROCESSES AND ANTIOXIDANT PROTECTION IN THE TREATMENT OF RATS THERMAL BURNING BY DOXICYCLINE AS A SYNTHETIC INHIBITOR OF MATRIX METALLOPROTEINASES IN EXPERIMENT.

Aim - to assess the effects of doxycycline on the state of lipid peroxidation processes and the activity of the antioxidant system. The study was performed on 144 rats of the WAG population weighing 200-250 g (6 rats in each group). Animals with thermal burns were injected with the test drug doxycycline, as well as reference drugs - thiotriazolin and methyluracil orally in starch suspensionafter thermal exposure and daily during the entire experiment period (28 days). Animals were removed from the experiment in accordance with the rules of bioethics on the 7th, 14th, 21st and 28th day. As a result of the research, the most intense influence of doxycycline on the processes of lipid peroxidation in the blood serum of rats was found - a decrease in DC activity by the end of the experiment (regardless of dose) and TBA-AP starting from the 14th day of observation reaching the value of intact rats (at a dose of 30 mg/kg). At the same time, an increase in the activity of enzymes of the antioxidant system was noted - the level of catalase from the 14th day (significantly higher than the control group regardless of dose) and the level of ceruloplasmin (from the second week of observation the indicator reached intact values ​​at a dose of 30 mg/kg). Reference drugs were inferior to doxycycline in their effectiveness. The data obtained may indicate the possibility of reducing the healing time of a thermal burn due to the suppression of excessive free radical oxidation activity and activation of antioxidant protection.

Kinetics of fragmentation and dissociation of two-strand protein filaments: Coarse-grained simulations and experiments.

While a significant body of investigations have been focused on the process of protein self-assembly, much less is understood about the reverse process of a filament breaking due to thermal motion into smaller fragments, or depolymerization of subunits from the filament ends. Indirect evidence for actin and amyloid filament fragmentation has been reported, although the phenomenon has never been directly observed either experimentally or in simulations. Here we report the direct observation of filament depolymerization and breakup in a minimal, calibrated model of coarse-grained molecular simulation. We quantify the orders of magnitude by which the depolymerization rate from the filament ends koff is larger than fragmentation rate k- and establish the law koff/k- = exp[(ε‖ - ε⊥)/kBT] = exp[0.5ε/kBT], which accounts for the topology and energy of bonds holding the filament together. This mechanism and the order-of-magnitude predictions are well supported by direct experimental measurements of depolymerization of insulin amyloid filaments.

Effect of Circulation Parameters on Functional Status of HepaRG Spheroids Cultured in Microbioreactor.

We studied the relationship between microcirculation parameters and functional status of HepaRG cells in spheroids and chose an optimal regimen within the physiologically permissible limits of mechanical impact for the cells that maintains the expression of functional genes of the liver.

Maintenance of High Cytochrome P450 Expression in HepaRG Cell Spheroids in DMSO-Free Medium.

We studied the effects of DMSO and fibroblasts during HepaRG cell spheroid formation and conditions of their subsequent culturing on the levels of mRNA of the major cytochromes P450. A protocol of spheroid formation from differentiated HepaRG cells and their culturing in serum- and DMSO-free medium is developed.

Mathematical and Experimental Model of Oxygen Diffusion for HepaRG Cell Spheroids.

3D cell cultures are extensively used to study in vitro toxic effect of xenobiotics. When using multicellular spheroids, the question about their optimal size should be solved: small spheroids are difficult to manipulate, while large size of spheroids impairs the transport of nutrients and oxygen into the center. Mathematical models describing the distribution of substances in multicellular spheroids numerical procedure for solving differential equation system, which complicates their use in laboratory practice. We proposed and experimentally evaluated a new mathematical model describing oxygen distribution in HepaRG cell spheroids. Markers of functional activity were studied in spheroids of different size. The maximum size of spheroids that can be maintained in culture for 9 days without necrosis was determined.

p53- and Caspase-3-Independent Mechanism of Acetaminophen Effect on Human Neural Cells.

Acetaminophen in a concentration of 5 mM increased the expression of JNK, HIF1A (hypoxiainduced factor), and CASP3, which indicated development of oxidative stress and apoptotic cell death. Acetaminophen in a concentration of 10 mM did not induce expression of HIF1A and CASP3, but reduced expression of chaperone HSP90, which attested to activation of a caspase-3-independent mechanism of cell death. The methods of preventing acetaminophen intoxication are discussed.

Epigenetic Mechanisms of Long-Term Effects of Mother-Infant Relationship on Physiology and Behavior of the Offspring.

The quality of mother-infant relationship in the early postnatal period influences the neurophysiology and behavior of adult animals via epigenetic mechanisms. The most studied target of long-term effects of early life events on physiology and behavior is hypothalamic-pituitary-adrenal axis, in particular, epigenetic programming of glucocorticoid receptor gene expression. Inhibition of histone deacetylases is a tool for epigenetic modulation of nervous system plasticity. Using this approach, it was demonstrated that epigenetic mechanisms play an important role in physiological and behavioral modifications. It is also promising tool for reversing the negative effects of disturbances in the mother-infant relationship early in life. To date, however, the use of histone deacetylase inhibitors is widespread in adult animals, while studies in the early postnatal period are still scarce despite their relevance.

[The cellular mechanisms and regulation of metastasis formation].

Recent data obtained at the junction of biochem: istry, molecular and cell biology and experimental oncology, showed that the formation of secondary foci of tumor growth during cancer progression--metastasis formation--is a highly determinate and regulated process. This process includes on the one hand the appearance of metastatic population of cells with special characteristics that allow their dissemination and seeding in distant organs and on the other.hand the formation of specific attractive micro environment in target organs. These cells show the ability to switch their motility to the most effective mode depending on the properties of the surrounding tissues (plasticity), appearance of specific receptors on the cell surface, which enhance their directed migration to target organs and acquisition of some characteristics of stem cells, allowing them to survive and reproduce in alien microenvironment. These alterations are strongly coordinated with development of a specific nichein the target organ which stimulates initiation and growth of a future metastasis, so-called premetastatic niche. In this review we analyzed recent data concerning mechanisms which regulate the emergence of metastatic population of cells, development of premetastatic niches and coordination of these processes:.

[Anti-inflammatory effect of therapeutic and low-frequency ultrasound on a rat model of inflammatory process].

The results of experimental investigations of the anti-inflammatory effect of ultrasound on the inflammatory process on a rat model of carrageenan-induced edema of the hind limb are given in this article. The technique used in the experiment showing ultrasound exposure parameters and how to control characteristics of the inflammatory process is described. The anti-inflammatory effect of ultrasound is established.

[The evaluation of changes in concentration of ghrelin, somatotropin, insulin-like growth factor-1, insulin, leptin and thyroid hormones in mother and umbilical blood in case of physiologic pregnancy with normosomia and macrosomia of fetus].

The sample of women with physiologic pregnancy consisting of 40 females with fetus normosomia and 8 females with fetus macrosomia were examined. The examination covered the evaluation of changes in concentration of ghrelin, somatotropin, insulin-like growth factor-I, insulin, leptin and thyroid hormones in mother and umbilical blood. In females with fetus macrosomia the changes in concentration of hormones regulating trophism, energy balance and anabolic processes in organisms of mother and fetus were detected

[Bacterial complexes of the fruiting bodies and hyphosphere of certain basidiomycetes].

The surface and internal tissues of the fruiting bodies of basidiomycetes were shown to be specific bacterial habitats characterized by varying diversity and structure of bacterial complexes. On the surface of fruiting bodies, gram-negative bacteria of the genera Pseudomonas, Xanthomonas, and Myxococcus prevailed, while in the internal tissues gram-positive bacteria of the genera Streptomyces, Bacillus, Arthrobacter, and Micrococcus were identified in addition. Bacterial complexes from the surface and inner tissues of the fruiting bodies of the studied basidiomycetes showed significant similarity to each other and differed from those from the hyphosphere and the reference soil. On the surface and in the internal tissues of the fruiting bodies, representatives of the genus Myxococcus were identified for the first time, which could indicate initial decay of the fruiting body.

CHEK2 I157T and colorectal cancer in Bulgaria.

PURPOSE: Germline variants of the CHEK2 gene have been shown to act as low-penetrance cancer susceptibility alleles for a wide range of human malignancies. CHEK2 I157T has particularly been linked to colorectal cancer (CRC) risk. We aimed at establishing the population frequency and contribution of this variant to colorectal carcinogenesis in Bulgaria. METHODS: We have genotyped 802 population controls and 343 CRC patients from Bulgaria for the CHEK2 I157T variant. RESULTS: Heterozygous were 9 of 343 patients (2.62%, odds ratio/OR=1.0, 95% confidence interval/CI = 0.42 - 2.33, p=0.99% and 21 of 802 controls (2.62%). Higher frequencies were found among patients with multiple polyposis (2/40, 5%, p=0.28) and the rarer mucinous histology (1/11, 9.09%, p= 0.26). CONCLUSION: We conclude that CHEK2 I157T is not relevant for CRC risk in Bulgaria, but studies on a larger scale might help evaluate its possible significance in respect to disease characteristics.

[Comparative research of normal and transformed fibroblast spreading. The role of microfilament polymerization and actin-myosin contractility].

Polymerization of microfilaments and their subsequent rearrangements under control of actin-myosin interactions are two main processes underlined morphogenetic reactions of cells. We studied their role during spreading of normal and transformed REF52tetRas fibroblasts with adjustable ras oncogene expression. Treatment with inhibitors of cell contractility (Y27532 or blebbistatin) led to disappearance of actin bundles and focal adhesions, but both normal and transformed cells preserved high pseudopodial activity. Spreading was considerably accelerated in normal cells and less accelerated in ras-transformed cells under these conditions. When actin polymerization was suppressed with low concentrations of latrunculin A, stress-fibrills and focal contacts were preserved, but lamellipodial activity was lost in normal cells, so spreading was dramatically inhibited. In the case of transformed fibroblasts, actin bundles and focal adhesions virtually disappeared, but pseudopofial activity was not lost and spreading was suppressed to a lesser extent. Therefore, the most essential process in regulation of cell spreading and polarization is microfilament polymerization at the leading edge. Incidentally, ras-transformed cells are less sensitive to inhibitors affecting cytoskeletal structure than non-transformed ones. Possible mechanisms underlying these diversities are discussed.

[Analysis of changes induced by oncogene N-RAS expression in pattern and distribution of pseudopodial activity of fibroblasts].

It is not known which morphological properties of fibroblasts induced by malignant transformation modulate their migration pattern. We studied the changes in the distribution and dynamics of the leading edge of 10(3) mouse fibroblasts after their transformation by oncogene N-RAS(asp13) and analyzed the changes in the pattern of cell migration. Transformation proved to increase the leading edge proportion and to considerably redistribute pseudopodial activity along the cell edge. As the result of transformation, small pseudopodia are formed in the stable lateral regions of the cell edge typical of normal fibroblasts, i.e., the lateral edge is no more truly stable. In addition, pseudopodial activity of the leading edge in transformed fibroblasts proved higher compared to normal ones. It is necessary to notice, the leading edge activity is equally high immediately after induction in both normal and transformed fibroblasts; although, it is suppressed with time in normal cells but not in transformed ones where it remains steadily high. These properties promote the random component of malignant cell motility and modify the cell migration pattern after transformation.

A study of nanosize Fe3O4 deposited on carbon matrix.

Nanosized crystalline Fe3O4 (with an average particle size of 16 nm) was successfully synthesized on a carbon matrix surface. The prepared sample was heat-treated in the temperature range 300 degrees C - 750 degrees C to remove residual impurities and to obtain a final product with a 77:23 ratio between magnetite and the carbon support. The sample was subjected to physicochemical and electrochemical tests. The purity of the phase and the particles size was determined by X-ray diffraction analysis and confirmed by field emission scanning electron micrographs. The specific surface area of the sample measured by the B.E.T method was 120 m2 g(-1). A series of electrochemical tests including EIS, CV and long-term constant current cycling have been performed. The obtained reversible capacity within 15 cycles was in the range 400-550 mA h x g(-1). The electrochemical behavior of the test sample and its possible practical use as an anode material in lithium secondary batteries are discussed.

[Biochemical features of gallbladder bile in biliary tract diseases].

Sixty-two and 58 patients with hypo- and hypermotor biliary tract dysfunction (BTD), respectively, as well as 59 patients with chronic acalculous cholecystitis (CAC) and 63 with opisthorchiasis-complicated CAC were examined. A control group comprised 33 patients of the same sex and age. All the patients underwent fractional duodenal intubation, followed by clinical, biochemical, and serological bile studies. All the examinees were found to increased gallbladder bile lithogenicity, minor changes being observed in biliary tract dysfunction and more pronounced ones being in opisthorchiasis. A biochemical study of gallbladder bile, followed by its lithogenicity correction, is recommended in the treatment of different forms of BTD.

[Experimental and clinical study of preparation Iridol action on the central nevros system].

In experiment on adult rats male the anxiolitic action of new plant origin drug Iridol, enriched with compounds iridoids, is shown. This effect of Iridol was approximately the same as by diazepam. In patients with arterial hypertension I - II degree, accompanied by psychoemotional disturbances, the use of Iridol in complex treatment increases efficacy of therapy.