105 research outputs found

    Role of foreign language teacher shaping students’ research skills

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    © 2015 Canadian Center of Science and Education. All rights reserved. Nowadays many foreign language teachers are not enough aware about the significance of the research component within their profile discipline, arguing that students even in their native language do not have enough use of fundamentals in their scientific professional activities. Therefore, this article is aimed to study the role of foreign language teacher when mastering students’ research skills in the process of learning English as a foreign language. The study results have confirmed that process of mastering students’ research skills when learning foreign language is directly connected with their teacher’s own research skill level. These article materials have practical value both for foreign language teachers and for students enrolled for foreign languages programs of education sciences faculties at high schools

    The role of the motor analyzer in the development of a child with trite dysarthria

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    В статье рассматривается роль двигательного анализатора в развитии детей дошкольного возраста со стертой дизартрией с учетом анализа уровневой организации движений.The article looks at the role of the motor analyzer in the development of preschool children with trite dysarthria taking into account analysis of the level-based organization of movements

    Влияние инсулинорезистентности на нарушение метаболизма глюкозы в миндалине головного мозга при экспериментальной болезни Альцгеймера

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    Purpose. Glucose metabolism is tightly regulated in the brain. Aberrant glucose metabolism is an important feature of neurodegenerative diseases, as inAlzheimer’s disease. The transport of glucose to the cell membrane is realized through the activity of insulin-regulated aminopeptidase (IRAP) which controls transfer of glucose transporter to the plasma membrane. IRAP is considered as one of the key markers of insulin resistance in Alzheimer’s disease. However, the question of the mechanism of the action of the IRAP remains open. The aim of the study was to study the effect of IRAP expression on cells of the neuronal and glial lineage, glucose transporter (GLUT4) expression in the brain amygdala on emotional memory in animals with experimental Alzheimer’s disease.Materials and methods. The study was performed with two experimental models of Alzheimer’s disease in mice. The experimental group was mice of the CD1 line, males aged 4 months (Alzheimer’s disease model with the intra-hippocampal administration of beta-amyloid 1-42 (1 µl) bilaterally in the CA1 area). The control group was mice of the CD1 line, males aged 4 months (sham-operated animals with the intrahippocampal administration of Phosphate buffered salin (1 µl) bilaterally in the CA1). The genetic model of Alzheimer’s disease is the B6SLJ-Tg line mice (APPSwFlLon, PSEN1*M146L*L286V) 6799Vas, males aged 4 months. The control group consisted of C57BL/6xSJL mice, males aged 4 months. Evaluation of emotional memory was carried out using “Fear conditioning” protocol. Expression of molecule-markers of insulin-resistance in the amygdala was studied by immunohistochemistry followed by confocal microscopy.Results. Aberrant associative learning and emotional memory was revealed in animals with an experimental model of Alzheimer’s disease. A decrease (p ≤ 0,05) of IRAP expression on cells of neuronal and glial nature, associated with GLUT4 down-regulation was detected in amygdala of brain in animals with experimental Alzheimer’s disease.Conclusion. Decreased number of IRAP-immunopositive neuronal and astroglial cells, as well as IRAP+/ GLUT4+ in cells of amygdala in animals with an experimental model of Alzheimer’s disease, indicates the development of insulin resistance in amygdala of brain, which was in correlation with the hippocampus in performing cognitive functions and memorizing associated with emotionally colored events. Цель. В головном мозге метаболизм глюкозы четко регулируется, поэтому его нарушение является важной особенностью нейродегенеративных заболеваний, в частности болезни Альцгеймера. Транспорт глюкозы в мембрану клетки реализуется за счет активности инсулин-регулируемой аминопептидазы (IRAP), которая влияет на память и обучение, и рассматривается как один из ключевых маркеров инсулинорезистентности при болезни Альцгеймера. Однако вопрос о механизме действия IRAP остается открытым. Цель исследования – изучение влияния экспрессии IRAP на клетках нейрональной и глиальной природы, а также совместно с инсулинзависимым глюкозным транспортером (GLUT4) в миндалине головного мозга на эмоциональную память у животных с экспериментальной болезнью Альцгеймера.Материал и методы. Исследование проводили на животных с использованием двух экспериментальных моделей болезни Альцгеймера – инъекционной и генетической. Опытная группа – мыши линии CD1, самцы в возрасте 4 мес, которым билатерально вводили бета-амилоид 1-42 в зону гиппокампа CA1 (сornu аmmonis)по 1 мкл. Контрольная группа – мыши линии CD1, самцы в возрасте 4 мес, которым билатерально вводили растворитель для бета-амилоида – фосфатно-солевой буфер в зону CA1 по 1 мкл.Генетическая модель болезни Альцгеймера – мыши линии B6SLJ –Tg(APPSwFlLon,PSEN1*M146L*L286 V)6799Vas, самцы в возрасте 4 мес. Контрольная группа – мыши линии C57BL/6xSJL, самцы в возрасте 4 мес. Оценку эмоциональной памяти проводили с использованием нейроповеденческого тестирования Fear conditioning. Экспрессию молекул-маркеров инсулинорезистентности в миндалине изучали методом иммуногистохимии с последующей конфокальной микроскопией.Результаты. У животных с экспериментальной моделью болезни Альцгеймера выявлено нарушение ассоциативного обучения и эмоциональной памяти. Выявлено снижение (р ≤ 0,05) экспрессии IRAP на клетках нейрональной и глиальной природы, а также (совместно с GLUT4) в миндалине головного мозга у животных с экспериментальной болезнью Альцгеймера.Заключение. Уменьшение числа IRAP-иммунопозитивных нейрональных и астроглиальных клеток, а также экспрессии IRAP/GLUT4 в клетках миндалины у животных с экспериментальной моделью болезни Альцгеймера указывает на развитие инсулинорезистентности в миндалине головного мозга, находящейся во взаимосвязи с гиппокампом при осуществлении когнитивных функций и запоминания, сопряженных с эмоционально окрашенными событиями.

    hTERT promoter activity and CpG methylation in HPV-induced carcinogenesis

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    <p>Abstract</p> <p>Background</p> <p>Activation of telomerase resulting from deregulated hTERT expression is a key event during high-risk human papillomavirus (hrHPV)-induced cervical carcinogenesis. In the present study we examined hTERT promoter activity and its relation to DNA methylation as one of the potential mechanisms underlying deregulated hTERT transcription in hrHPV-transformed cells.</p> <p>Methods</p> <p>Using luciferase reporter assays we analyzed hTERT promoter activity in primary keratinocytes, HPV16- and HPV18-immortalized keratinocyte cell lines and cervical cancer cell lines. In the same cells as well as cervical specimens we determined hTERT methylation by bisulfite sequencing analysis of the region spanning -442 to +566 (relative to the ATG) and quantitative methylation specific PCR (qMSP) analysis of two regions flanking the hTERT core promoter.</p> <p>Results</p> <p>We found that in most telomerase positive cells increased hTERT core promoter activity coincided with increased hTERT mRNA expression. On the other hand basal hTERT promoter activity was also detected in telomerase negative cells with no or strongly reduced hTERT mRNA expression levels. In both telomerase positive and negative cells regulatory sequences flanking both ends of the core promoter markedly repressed exogenous promoter activity.</p> <p>By extensive bisulfite sequencing a strong increase in CpG methylation was detected in hTERT positive cells compared to cells with no or strongly reduced hTERT expression. Subsequent qMSP analysis of a larger set of cervical tissue specimens revealed methylation of both regions analyzed in 100% of cervical carcinomas and 38% of the high-grade precursor lesions, compared to 9% of low grade precursor lesions and 5% of normal controls.</p> <p>Conclusions</p> <p>Methylation of transcriptionally repressive sequences in the hTERT promoter and proximal exonic sequences is correlated to deregulated hTERT transcription in HPV-immortalized cells and cervical cancer cells. The detection of DNA methylation at these repressive regions may provide an attractive biomarker for early detection of cervical cancer.</p

    Особенности пролиферации и миграции клеток головного мозга при когнитивном тренинге животных с экспериментальной болезнью Альцгеймера

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    Aims. Alzheimer’s disease is a multifactorial neurodegenerative disease characterized by the presence of amyloid beta peptide containing plaques, and neurofibrillary tangles. Beta-amyloid is a major risk factor and it plays a central role in the onset and progression of Alzheimer’s disease. However, question of the influence of beta-amyloid on neurogenesis in the hippocampus in the adult brain is still open. The purpose of this paper is to study cognitive functions and their association with proliferation, survival and migration of newly-formed cells in normal adult rat brain and in the experimental Alzheimer’s disease.Materials and methods. Rats (Wistar, males, 7 months) were used. Experimental group (Alzheimer’s disease model with the intrahippocampal administration of beta-amyloid 1-42 (5 µl) bilaterally in the CA1 area) and a control group (sham-operated animals with the intrahippocampal administration of Phosphate buffered salin (5 µl) bilaterally in the CA1) have been tested. The study was conducted from February to July. Neurobehavioral test (Morris water maze) was used to assess working memory and memory consolidation. The study of cell migration was performed by introducing bromodeoxyuridine (50 mg/kg). Expression of neurogenesis markers in the subgranular zone of the dentate gyrus of the hippocampus was studied has been studied with indirect immunohistochemistry for free-floating sections followed by the confocal microscopy.Results. Modelling of Alzheimer’s disease leads to impaired cognitive function and memory in animals. We found that these events were associated with the suppression of proliferative (р = 0,043) and migratory activity of brain cells (р = 0,031), but not survival of cells (p = 0,985) compared to the control group.Training in Morris water maze of animals with experimental Alzheimer’s disease promotes migration of progenitor cells along the rostral migration way (р = 0,011) compared with the group without training. However, the number of neuroblasts (р = 0,809) and proliferation of neuronal progenitor cells (p = 0,083) were not significantly affected compared with the group without training.Conclusions. Decreased level of brain cells proliferation, alterations in their migration and development of cognitive dysfunction have been found in the rat model of Alzheimer’s disease, thus suggesting impairment of neurogenesis induced by amyloid. Possible involvement of local insulin resistance into the development of neurogenesis alterations is discussed.Болезнь Альцгеймера является многофакторным нейродегенеративным заболеванием, характеризующимся наличием бета-амилоидных бляшек и нейрофибриллярных клубков. Бета-амилоид является важным фактором риска и играет центральную роль в возникновении и прогрессировании болезни Альцгеймера. Однако вопрос о влиянии бета-амилоида на гиппокампальный нейрогенез во взрослом мозге остается открытым.Цель исследования – изучение влияния процесса обучения на нейрогенез, пролиферацию, выживаемость и миграцию клеток в норме и при экспериментальной болезни Альцгеймера.Материал и методы. Исследование выполнено на самцах зрелых крыс линии Wistar в возрасте 7 мес. Опытная группа – животные с экспериментальной болезнью Альцгеймера после введения бета-амилоида 1-42 в CA1 зону гиппокампа билатерально по 5 мкл. Контрольная группа – ложно-оперированные животные, которым вводили растворитель для бета-амилоида – фосфатно-солевого буфера – в CA1 зону билатерально по 5 мкл. Для оценки рабочей памяти, а также консолидации памяти использовали нейроповеденческое тестирование в водном лабиринте Морриса. Изучение миграции клеток осуществляли путем введения бромдезоксиуридина (50 мг/кг). Экспрессию молекул-маркеров нейрогенеза (Ki-67, PSA-NCAM, PCNA) в гиппокампе исследовали методом иммуногистохимии с последующей конфокальной микроскопией.Результаты. Показано, что моделирование болезни Альцгеймера приводит к нарушениям когнитивных функций и запоминания у животных. В группе с экспериментальной болезнью Альцгеймера выявлено снижение уровня пролиферации клеток (р = 0,043), нарушение миграции (р = 0,031), но не выживаемости клеток (р = 0,985) по сравнению с контрольной группой. Обучение в водном лабиринте Морриса животных с экспериментальной болезнью Альцгеймера способствует миграции клеток-предшественников по ростральному миграционному пути (р = 0,011). Количество нейробластов (р = 0,809) и пролиферация клеток-предшественников нейронов (р = 0,083) значимо не меняется по сравнению с группой без обучения.Заключение. При моделировании болезни Альцгеймера у животных наблюдается когнитивная дисфункция, снижение уровня пролиферации и миграции клеток, что свидетельствует о нарушении нейрогенеза за счет токсического действия амилоида. Обсуждается связь полученных результатов с механизмами развития локальной инсулинорезистентности

    DNA Methyltransferase Controls Stem Cell Aging by Regulating BMI1 and EZH2 through MicroRNAs

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    Epigenetic regulation of gene expression is well known mechanism that regulates cellular senescence of cancer cells. Here we show that inhibition of DNA methyltransferases (DNMTs) with 5-azacytidine (5-AzaC) or with specific small interfering RNA (siRNA) against DNMT1 and 3b induced the cellular senescence of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) and increased p16INK4A and p21CIP1/WAF1 expression. DNMT inhibition changed histone marks into the active forms and decreased the methylation of CpG islands in the p16INK4A and p21CIP1/WAF1 promoter regions. Enrichment of EZH2, the key factor that methylates histone H3 lysine 9 and 27 residues, was decreased on the p16INK4A and p21CIP1/WAF1 promoter regions. We found that DNMT inhibition decreased expression levels of Polycomb-group (PcG) proteins and increased expression of microRNAs (miRNAs), which target PcG proteins. Decreased CpG island methylation and increased levels of active histone marks at genomic regions encoding miRNAs were observed after 5-AzaC treatment. Taken together, DNMTs have a critical role in regulating the cellular senescence of hUCB-MSCs through controlling not only the DNA methylation status but also active/inactive histone marks at genomic regions of PcG-targeting miRNAs and p16INK4A and p21CIP1/WAF1 promoter regions

    Isolation and Characterization of Novel Murine Epiphysis Derived Mesenchymal Stem Cells

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    BACKGROUND: While bone marrow (BM) is a rich source of mesenchymal stem cells (MSCs), previous studies have shown that MSCs derived from mouse BM (BMMSCs) were difficult to manipulate as compared to MSCs derived from other species. The objective of this study was to find an alternative murine MSCs source that could provide sufficient MSCs. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we described a novel type of MSCs that migrates directly from the mouse epiphysis in culture. Epiphysis-derived MSCs (EMSCs) could be extensively expanded in plastic adherent culture, and they had a greater ability for clonogenic formation and cell proliferation than BMMSCs. Under specific induction conditions, EMSCs demonstrated multipotency through their ability to differentiate into adipocytes, osteocytes and chondrocytes. Immunophenotypic analysis demonstrated that EMSCs were positive for CD29, CD44, CD73, CD105, CD166, Sca-1 and SSEA-4, while negative for CD11b, CD31, CD34 and CD45. Notably, EMSCs did not express major histocompatibility complex class I (MHC I) or MHC II under our culture system. EMSCs also successfully suppressed the proliferation of splenocytes triggered by concanavalin A (Con A) or allogeneic splenocytes, and decreased the expression of IL-1, IL-6 and TNF-α in Con A-stimulated splenocytes suggesting their anti-inflammatory properties. Moreover, EMSCs enhanced fracture repair, ameliorated necrosis in ischemic skin flap, and improved blood perfusion in hindlimb ischemia in the in vivo experiments. CONCLUSIONS/SIGNIFICANCES: These results indicate that EMSCs, a new type of MSCs established by our simple isolation method, are a preferable alternative for mice MSCs due to their better growth and differentiation potentialities

    Mechanisms of human telomerase reverse transcriptase (hTERT) regulation: clinical impacts in cancer

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    Background Limitless self-renewal is one of the hallmarks of cancer and is attained by telomere maintenance, essentially through telomerase (hTERT) activation. Transcriptional regulation of hTERT is believed to play a major role in telomerase activation in human cancers. Main body The dominant interest in telomerase results from its role in cancer. The role of telomeres and telomere maintenance mechanisms is well established as a major driving force in generating chromosomal and genomic instability. Cancer cells have acquired the ability to overcome their fate of senescence via telomere length maintenance mechanisms, mainly by telomerase activation. hTERT expression is up-regulated in tumors via multiple genetic and epigenetic mechanisms including hTERT amplifications, hTERT structural variants, hTERT promoter mutations and epigenetic modifications through hTERT promoter methylation. Genetic (hTERT promoter mutations) and epigenetic (hTERT promoter methylation and miRNAs) events were shown to have clinical implications in cancers that depend on hTERT activation. Knowing that telomeres are crucial for cellular self-renewal, the mechanisms responsible for telomere maintenance have a crucial role in cancer diseases and might be important oncological biomarkers. Thus, rather than quantifying TERT expression and its correlation with telomerase activation, the discovery and the assessment of the mechanisms responsible for TERT upregulation offers important information that may be used for diagnosis, prognosis, and treatment monitoring in oncology. Furthermore, a better understanding of these mechanisms may promote their translation into effective targeted cancer therapies. Conclusion Herein, we reviewed the underlying mechanisms of hTERT regulation, their role in oncogenesis, and the potential clinical applications in telomerase-dependent cancers.info:eu-repo/semantics/publishedVersio

    The Eurasian Modern Pollen Database (EMPD), version 2

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    The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019)Swiss National Science Foundation | Ref. 200021_16959
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