45 research outputs found

    Increasing Notch signaling antagonizes PRC2-mediated silencing to promote reprograming of germ cells into neurons

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    Cell-fate reprograming is at the heart of development, yet very little is known about the molecular mechanisms promoting or inhibiting reprograming in intact organisms. In the C. elegans germline, reprograming germ cells into somatic cells requires chromatin perturbation. Here, we describe that such reprograming is facilitated by GLP-1/Notch signaling pathway. This is surprising, since this pathway is best known for maintaining undifferentiated germline stem cells/progenitors. Through a combination of genetics, tissue-specific transcriptome analysis, and functional studies of candidate genes, we uncovered a possible explanation for this unexpected role of GLP-1/Notch. We propose that GLP-1/Notch promotes reprograming by activating specific genes, silenced by the Polycomb repressive complex 2 (PRC2), and identify the conserved histone demethylase UTX-1 as a crucial GLP-1/Notch target facilitating reprograming. These findings have wide implications, ranging from development to diseases associated with abnormal Notch signaling

    The influence of rifle carriage on the kinetics of human gait

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    The inļ¬‚uence that riļ¬‚e carriage has on human gait has received little attention in the published literature. Riļ¬‚e carriage has two main eļ¬€ects, to add load to the anterior of the body and to restrict natural arm swing patterns. Kinetic data were collected from 15 male participants, with 10 trials in each of four experimental conditions. The conditions were: walking without a load (used as a control condition); carrying a lightweight riļ¬‚e simulator, which restricted arm movements but applied no additional load; wearing a 4.4 kg diving belt, which allowed arms to move freely; carrying a weighted (4.4 kg) replica SA80 riļ¬‚e. Walking speed was ļ¬xed at 1.5 m/s (+5%) and data were sampled at 400 Hz. Results showed that riļ¬‚e carriage signiļ¬cantly alters the ground reaction forces produced during walking, the most important eļ¬€ects being an increase in the impact peak and mediolateral forces. This study suggests that these eļ¬€ects are due to the increased range of motion of the bodyā€™s centre of mass caused by the impeding of natural arm swing patterns. The subsequent eļ¬€ect on the potential development of injuries in riļ¬‚e carriers is unknown

    RESULTS OF THE EXAMINATION OF HYGIENIC STATE OF ORAL CAVITY AND PERIODONTIUM TISSUES IN CHILDREN AND TEENAGERS OF IRKUTSK

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    At the present moment periodontium tissues diseases are often registered in the population of children and teenagers. The article shows the interrelation of progress of periodontium tissues diseases with hygienic state of oral cavity. In this article we showed thatfirst evident manifestations of periodontium tissues diseases are revealed in thisgroup of patients at the age of eight. Number of diseases increases (up to 13,61 Ā± 2,48 %] and their severity grows with the increase of years. Th is is related to the h igh level (up to 45,45 %) of unsatisfactory hygienic state of oral cavity of examined children and teenagers

    Changes in the oxidative-antioxidant status of blood in freestyle wrestlers under the influence of physical exertion

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    Purpose of the study: to evaluate the ā€œlipid peroxidation-antioxidant protectionā€ system in freestyle wrestlers under the influence of intense physical activity in order to identify the nature of oxidative processes and the antioxidant status of the athletesā€™ body.Materials and methods: the study involved athletes ā€” freestyle wrestlers, boys 18ā€“22 years old, with sports qualifications: candidate master of sports or master of sports, regularly involved in freestyle wrestling. The control group consisted of students who did not have a sports category and were not involved in sports activities, comparable in gender, age, weight category with the comparison group. Ā The material for the study was plasma and red blood cells. Blood sampling from athletes was carried out twice, at the end of the preparatory and competitive periods, in the morning, on an empty stomach from the ulnar vein, in accordance with generally accepted requirements. Components of lipid peroxidation and antioxidant defense were determined using spectrophotometric and fluorometric methods.Results: it was found that in athletes after intense physical activity (competitive period), there is a significantly significant decrease in substrates with double bonds by 61 %, primary products by 59 % and intermediate products by 44 %, an increase in the final products of lipid peroxidation by 25 % against the background of inhibition activity of antioxidant protection components: retinol by 40 %, superoxide dismutase by 7 % and reduced glutathione by 11 %.Conclusion: The level of free radical processes increases during physical activity due to the accumulation of oxygen in organs and tissues, and depends on the intensity and duration of the exercise. In the course of the study, it was established that the preparatory and competitive periods, in comparison with the control group, among freestyle wrestlers, depending on the previous level of physical activity, are characterized by activation of lipid peroxidation processes and inhibition of enzymatic and non-enzymatic components of antioxidant protection. The established changes are recommended to be taken into account when conducting comprehensive rehabilitation of athletes, when developing recommendations for improving the training process, as well as when using antioxidant complexes for athletes aimed at restoring various parts of the bodyā€™s antioxidant defense

    Survival through networks: the 'grip' of the administrative links in the Russian post-Soviet context

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    Ā© 2014 Taylor & Francis. Based on an analysis of the post-Soviet transformation experience of four defence sector organizations in a Russian region where the defence sector occupies a substantial part of the local economy, this article develops a typology of network relationships: Grooved Inter-relationship Patterns (Grā€™ip) networks and Fluid Inter-relationship Patterns (Flā€™ip) networks. This typology can be applied to a range of transition/emerging market and low system trust contexts. Grā€™ip networks, in this case, represent the persisting legacy of the Soviet command-administrative system. Flā€™ip networks are here an attempt by the defence companies to link into the civilian supply chains of a developing market economy. This article argues that Grā€™ip networks had and still have a crucial role to play in Russian enterprisesā€™ survival and development

    Features of lipid peroxidation and antioxidant protection in Mongoloid men, carriers of non-functional polymorphisms of GSTT1 and GSTM1 genes, with different status of fertility

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    Background. Genetic factors cause 30-50 % of cases of male infertility different forms. We have conducted the investigation of the lipid peroxidation and antioxidant protection system components, associated with the biotransformation genes polymorphisms, in men with infertility. Aims: to study parameters of lipid peroxidation and antioxidant defense system associated with polymorphisms of biotransformation genes in infertile Mongoloid men. Materials and methods. The main group included 143 men of reproductive age from Mongoloid population who came to the Public Health Institution "Republican Perinatal Center" in Ulan-Ude with the problem of one year and more infertility after the marriage. Fifty-three almost healthy males with proven fertility were included in the control group. Blood samples of all men were genotyped by glutathione S-transferase (GSTP1, GSTM1, GSTT1) gene family and activity of glutathione system enzymes was determined. Results. In the fertile Mongoloids with non-functional genotype GSTT1(0/0)/GSTM1(0/0) we have established an increase concentration of a-tocopherol in serum, activity of glutathione peroxidase and a decrease in glutathione-S-transferase, as well as a decrease in the concentration of a-tocopherol. In infertile Mongoloids with non-functional GSTT1(0/0)/ GSTM1 (0/0) genotypes, an increase in the tiobarbituric acid reactants, glutathione peroxidase and a decrease in the concentration of a-tocopherol was found in the ejaculate; we also detected a decrease in the concentration of a-tocopherol, the level of oxidized glutathione and glutathione-s-transferase activity. Conclusions. Genetically determined peculiarities of functioning of the xenobiotic biotransformation system make each individual unique with regard to their adaptive capacity - resistance or sensibility to the damaging exo- and endogenous factors

    FEATURES OF ANTIOXIDANT SYSTEM STATE IN ADOLESCENTS OF EASTERN SIBERIA IN DEPENDS ON THEIR GENDER AND ETHNIC ORIGIN

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    This research is devoted to studying of features of antioxidant protection system in adolescent boys and girls of various ethnic groups of Eastern Siberia. Study of the peculiarities of processes of antioxidant protection of populations of people of different ethnicity, living in the same geographical conditions, is of undoubted scientific interest. It is especially important to assess metabolic status of a young, growing body to ensure in the future the preservation of reproductive ability. We biochemically evaluated 58 boys of 14-17 years old. Out of them 19 boys were Russian, 29 boys were Buryat population and 10 boys were metises. Also we biochemically evaluated 57 girls. Out of them 21 were Russian, 27 girls were Buryat population and 9 girls were metises. The materials for biochemical studies were blood serum and red cells. The total antioxidant activity of serum and the content of its components (superoxide dismutase, Ī±-tocopherol, retinol, blood-reduced glutathione) were evaluatedbya spectrofluomphotometer Ā«SHIMADZU-1501Ā» (Japan). Statistical analysis was performed by parametric tests. The study was supported by grants of the President ofthe Council of the Russian Federation (Scientific School 494.2012.7). The detected features of antioxidant protection processes in observed adolescents had gender differences, also may be explained by their ethnicity and characterized by different degree of activity of metabolic processes in adolescent boys and girls of different ethnic groups of Eastern Siberia. Study the state of the antioxidant system of the organism can be used as an additional criterion for complex examination of practically healthy adolescents, which significantly enhance the representation about the adaptation possibilities of the organism to external conditions and can be a basis for effective monitoring of reproductive health in the future

    Modern concepts of viral hepatitis (review of literature)

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    We conducted an analysis of Russian and foreign literature and an analysis of our researches on the problem of etiology and pathogenesis of viral hepatitis was showed. Viral hepatitis occupies a leading position among infectious disease. Chronic forms of viral hepatitis B and C is the most prevalent. Among them more than 60 % are registered in age from 20 to 39 years. In spite of the fact that pathogenesis, clinical aspects and chronization of these forms are different, they have the general processes in a liver. The changes of these processes of the general systems of an organism (such as the neuroendocrine regulation, lipid status and lipid peroxidation - antioxidant system) have the particular importance. Studying these variables under abnormalities of reproductive health in women with hepatitis is particularly topical

    THE CHANGES OF FUNCTIONAL ACTIVITY OF A THYROID AND METABOLISM OF THYROID HORMONES IN TEENAGED GIRLS IN DIFFERENT ETHNIC GROUPS OF EASTERN SIBERIA AS AN IMPORTANT COMPONENT OF LONG-TERM ADAPTATION TO EXTREME CLIMATIC AND GEOGRAPHICAL CONDITIONS OF LIVING

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    Girls and teenaged girls of different ethnic groups living in Tofalaria during different age period were examined. The aim of this research was to establish the peculiarities of functioning of pituitary-thyroid system and metabolism of thyroid hormones in healthy girls and teenagers living under adverse climatic and geographical conditions depending on their ethnicity. It was set that in ethnic Tofs girls and in Europoids girls in age group of 7-11 there were differences in the content of the active fractions of thyroid hormones testifying different mechanisms of maintenance of thyroid homeostasis. These differences remain in age group of 12-14, when changes in pituitary section of the system are added to them. The functioning of pituitary-thyroid system-level of neuro-endocrine regulation in native girls of Tofalaria of 15-18 goes in more economical way. This is actually the result of genetically determined long-term adaptation of natives' organism to extreme climatic and geographical environmental factors
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