53 research outputs found

    Structural and transport characteristics of substituted bismuth niobates

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    The results of studying solid solutions with the composition of Bi 3Nb1 - y Zr y O7 ± δ, Bi2.95Y0.05Nb1 - y Zr y O 7 ± δ (y = 0-0.5; Δy = 0.1), and Bi 6.95Y0.05Nb2 - y Zr y O 15.5 (y = 0.1-1; Δy = 0.1) are presented. XRD and electron microscopy with X-ray microanalysis are used to determine the homogeneity regions of solid solutions; crystallochemical parameters are calculated. It is shown that irrespective of the ratio of Bi: Nb, two cubic phases are formed at an increase in the dopant amount. One of these represents a solid solution based on Bi3NbO7 (δ-phase) and the second one is a solid solution based on δ-Bi2O3 (δ′-phase). Conductivity of sintered samples is studied using the impedance spectroscopy technique. Introduction of yttrium into the bismuth sublattice results in no increase in conductivity of solid solutions, while in the case of the ratio of Bi: Nb = 3: 1, overall conductivity of solid solutions is somewhat higher at similar dopant concentrations. © 2013 Pleiades Publishing, Ltd

    Assessment of genetic diversity of some Siberian and Far Eastern species of the genus Spiraea (Rosaceae) by newly developed multiplex panels of nuclear SSR loci

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    Taxonomic and population genetic studies of the genus Spiraea (Rosaceae) species require new informative genetic markers. We screened 37 previously published heterologous oligonucleotide primer pairs for nuclear microsatellite loci and selected eight polymorphic and most reproducible of them for PCR multiplexing which substantially increases performance of routine mass genotyping. Three multiplex sets of 3, 3 and 2 loci, respectively, were developed and tested for ability to estimate the parameters of genetic variability and  population  structure in closely related species Spiraea ussuriensis, S. f lexuosa, S. chamaedryfolia representing seven natural populations of the Russian Far East and Siberia. Allele number ranged among loci from twelve (Spth20) to three. Among 41 alleles found, 7 were unique in some species/populations. Analysis of parameters of genetic variability in Spiraea spp. showed similar values of allele number per locus and observed heterozygosity among populations and slightly greater estimates of expected hete rozygosity in the samples of S. f lexuosa (NA = 2.387; HO = 0.387 ± ± 0.052; HE = 0.540 ± 0.055) as compared to S. ussuriensis (NA = = 2.781; HO = 0.385 ± 0.079; HE = 0.453 ± 0.072) and S. chamaedryfolia (NA = 2.875; HO = 0.331 ± 0.071; HE = 0.505 ± 0.069). The observed values of genetic polymorphism parameters indicate the average level of genetic diversity of the studied species typical to previous studies in Spiraea. About 19 % of the observed variability occurred among populations (FST = 0.191) while 81 % of the total genetic variation concentrated within the populations. The loci VS11, VS12, VS2, and VS6 contributed most to the observed differentiation. Nei genetic distances  between populations ranged from 0.049 to 0.585. Genetic differentiation patterns among studied populations based on allele frequencies of nuclear microsatellite loci correspond with their geographical location. Genetic composition of some samples contradicted with their provisional species identification

    Role of parathyroid hormone-related protein in breast cancer detection and prognosis

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    Currently, there are limited data supporting the use of parathyroid hormone-related protein for the purposes of breast cancer detection and disease prognosis. This literature review covers research results on diagnostic potential of parathyroid hormone-related protein as a biomarker for breast cancer, as well as the information available in the scientific literature, reflecting obvious contradictions regarding clinical and prognostic importance of this protein in the primary breast cancer, correlation of its expression with the risk of bone metastasis and survival of patients. Results of preclinical and clinical research show, that parathyroid hormone-related protein inhibits tumor progression and decreases its metastasis at early stages of the disease, which improves the survival rate, but it has an opposite effect at the advanced stages of cancer, as it increases tumor development and metastasis, and reduces survival rates. Altogether, these studies prove an idea that parathyroid hormone-related protein plays a double role in breast cancer. Use of parathyroid hormone-related protein for breast cancer early detection and disease prognosis is currently becoming a subject of detailed scientific research studies, which is confirmed by the facts presented in this literature review

    ASSESSMENT OF CEREBRAL PERFUSION IN PATIENTS WITH HEMODYNAMIC ISCHEMIC STROKE UNDERGOING RECONSTRUCTIVE BRACHIOCEPHALIC ARTERY INTERVENTIONS

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    The paper deals with the assessment of cerebral perfusion in patients in the acute period of acute cerebrovascular accident before and after revascularization surgery. It gives a clinical example of using contrast-free perfusion magnetic resonance imaging (MRI) in a patient with hemodynamic ischemic stroke. The use of this technique made it possible to determine indications for early carotid endarterectomy for the contralateral internal carotid artery and to evaluate positive postoperative changes in cerebral perfusion and the patient’s neurological status. The authors analyzed the current literature on this problem with a particular emphasis on the possibilities of using dynamic susceptibility contrast-enhanced and arterial spin-labeling contrast-free perfusion MRI in this category of patients. Carotid endarterectomy in the acute period of acute cerebrovascular accident can improve cerebral hemodynamics and the patient’s neurological status and prevent recurrent cerebral circulatory disorders. Indications for this surgery should be determined by taking into consideration the results of perfusion MRI techniques (single-photon computed tomography contrastenhanced and contrast-free perfusion MRI)

    Клиническое 9-месячное наблюдение орбитального венозного варикоза с внутрипросветным тромбом с использованием лучевых методов

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    A rare clinical case of thrombosis of varicose superior ophthalmic vein in combination with a unilateral venous anomaly of the subcortical region of the brain with successful antithrombotic therapy is presented. Varicose veins of the superior ophthalmic vein are rare (2% of all orbital formations) and are a risk factor for thrombosis.Material and methods. A 41-year-old patient with verified thrombosis of unilateral orbital venous varicose veins was observed for 9 months. Initially, MSCT of the brain and MSCT angiography were performed, then dynamic monitoring was carried out by performing MRI of the brain and MR venography, and finally an ultrasound examination of the orbit was performed.Description of a clinical case. The clinical presentation consisted of a slight non-pulsatile unilateral exophthalmos, mild ptosis, periorbital soft tissue edema, subconjunctival hemorrhage, paraorbital hematoma, and venous dysfunction in the fundus. MSCT and MSCT angiography revealed a thrombus inside the sac of orbital venous varicose veins. The disease was probably secondary in nature, given that it was combined with venous angioma of the subcortical region on the same side. During 9 months of observation, to monitor the effectiveness of therapy, MRI was performed three times before and after contrast enhancement, which showed a gradual decrease in exophthalmos, the size of the thrombus and the varicocele sac, which was accompanied by a gradual improvement in the clinical picture until subjective recovery.Conclusion. MRI was as good an imaging modality as MSCT, and, in our opinion, more preferable due to the absence of radiation exposure and the need for iodine contrast agent.Представлен редкий клинический случай тромбоза варикозно расширенной верхней глазничной вены в сочетании с унилатеральной венозной аномалией развития подкорковой области головного мозга с успешной антитромботической терапией. Варикозное расширение верхней глазничной вены встречается редко (2% от всех образований орбиты), является предрасполагающим фактором тромбоза вены.Материал и методы. Пациентка 41 года с верифицированным тромбозом одностороннего орбитального венозного варикоза наблюдалась в течение 9 мес. Первично выполнены МСКТ головного мозга и МСКТ-ангиография, затем динамическое наблюдение осуществлялось выполнением МРТ головного мозга и МР-венографии, в заключение выполнено УЗИ орбиты.Описание клинического наблюдения. Клиническая картина состояла из небольшого непульсирующего одностороннего экзофтальма, легкого птоза, периорбитального отека мягких тканей, подконъюнктивального кровоизлияния, параорбитальной гематомы, венозной дисфункции на глазном дне. При МСКТ и МСКТ-ангиографии обнаружен тромб внутри мешка орбитального венозного варикоза. Заболевание, вероятно, носило вторичный характер, учитывая, что сочеталось с венозной ангиомой подкорковой области с той же стороны. В течение 9 мес наблюдения для контроля эффективности терапии трижды выполнялась МРТ до и после контрастного усиления, которая показала постепенное уменьшение экзофтальма, размеров тромба и мешка варикоцеле, что сопровождалось постепенным улучшением клинической картины до субъективного выздоровления.Заключение. МРТ явилась столь же хорошим методом визуализации, как и МСКТ, и, на наш взгляд, более предпочтительным из-за отсутствия лучевой нагрузки и необходимости применения йодистого контрастного средства

    ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries

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    This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors

    Количественное определение моноаминовых нейротрансмиттеров в гомогенатах головного мозга крыс с помощью ВЭЖХ-МС/МС

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    Relevance. Evaluation of the effect of drugs on neurotransmitter processes is an important component of pharmacodynamic studies. The quantitative determination of monoamine neurotransmitters in the brain structures of laboratory animals is an urgent task of pharmacology and physiology.Purpose of the study. Development of a method for the quantitative determination of serotonin, dopamine, norepinephrine, histamine and epinephrine in rat brain homogenates using HPLC-MS/MS.Methods. The isolation of neurotransmitters from the brain of rats was carried out by homogenizing the biomaterial with acetonitrile and hydrochloric acid. The extraction was purified by liquid-liquid extraction with chloroform and isopropanol. Monoamines were detected using an AB Sciex QTrap 3200MD mass spectrometer, chromatography was performed using an Agilent Technologies 1260 Infinity II HPLC. Methanol and deionized water were used as eluent.Results. Sample preparation consisted of centrifugation of the resulting homogenate, drying of the supernatant in a stream of nitrogen, dissolution of the precipitate in the mobile phase, and purification of the solution using a mixture of chloroform and isopropanol. An Agilent InfinityLab Poroshell 120 EC-C18 4.6×100 mm, 2.7 μm analytical column was used to separate monoamine neurotransmitters. The total time of the chromatographic analysis was 12 minutes, the retention time of norepinephrine, epinephrine, dopamine, serotonin, histamine was 2.8; 3.2; 5.4; 7.9; and 2.2 minutes, respectively. The analytical range of the technique was 25.0–5000.0 ng/g for epinephrine, histamine, and dopamine; 5.0–5000.0 ng/g for serotonin and 50.0–5000.0 for norepinephrine. To test the technique, we analyzed monoamine neurotransmitters in the striatum of intact Wistar rats.Conclusion. The developed bioanalytical HPLC-MS/MS method for the quantitative determination of monoamine neurotransmitters in the rat brain fully complies with the validation requirements. The metrological characteristics of the technique make it possible to estimate the content of norepinephrine, epinephrine, dopamine, serotonin, and histamine in the brain structures of rats with high accuracy.Актуальность. Оценка влияния лекарственных средств на нейромедиаторные процессы является важной составляющей фармакодинамических исследований. Количественное определение моноаминовых нейротрансмиттеров в структурах головного мозга лабораторных животных является актуальной задачей фармакологии и физиологии.Цель – разработка методики количественного определения серотонина, дофамина, норэпинефрина, гистамина и эпинефрина в гомогенатах головного мозга крыс с помощью ВЭЖХ-МС/МС.Методы. Выделение нейромедиаторов из мозга крыс осуществляли путём гомогенизации биоматериала с ацетонитрилом и хлористоводородной кислотой. Очистку извлечения проводили с помощью жидкость-жидкостной экстракции с хлороформом и изопропанолом. Детектирование моноаминов осуществляли с помощью масс-спектрометра AB Sciex QTrap 3200MD, хроматографирование проводили с использованием ВЭЖХ Agilent Technologies 1260 Infinity II. В качестве элюента использовали метанол и деионизированную воду.Результаты. Пробоподготовка представляла собой центрифугирование полученного гомогената, высушивание супернатанта в токе азота, растворение осадка в подвижной фазе, очистку раствора с помощью смеси хлороформа и изопропанола. Для хроматографического разделения моноаминовых нейромедиаторов использовали аналитическую колонку Agilent InfinityLab Poroshell 120 EC-C18 4,6 × 100 мм, 2,7 мкм. Общее время хроматографического анализа составило 12 минут, время удерживания норэпинефрина, эпинефрина, дофамина, серотонина, гистамина составило 2,8; 3,2; 5,4; 7,9; и 2,2 минут, соответственно. Аналитический диапазон методики составил 25,0–5000,0 нг/г для эпинефрина, гистамина и дофамина; 5,0–5000,0 нг/г для серотонина и 50,0–5000,0 для норэпинефрина. Для апробации методики был проведён анализ моноаминовых нейромедиаторов в стриатуме интактных крыс Wistar. Заключение. Разработанная биоаналитическая ВЭЖХ-МС/МС-методика количественного определения моноаминовых нейромедиаторов в головном мозге крыс полностью соответствует валидационным требованиям. Метрологические характеристики методики позволяют с высокой точностью оценить содержание норэпинефрина, эпинефрина, дофамина, серотонина и гистамина в структурах головного мозга крыс

    The Flow Cytometry Study of Cellular Immunity in Rhesus Monkeys after Experimental Infection with SARS CoV 2 Virus

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    Cellular immunity plays an important role in the pathogenesis and formation of protective immune defense against the SARS‑CoV‑2 virus.The aim of the work was to study the cellular immunity of rhesus monkeys applying flow cytometry after experimental infection with the SARS‑CoV‑2 virus.Materials and methods. Male rhesus monkeys were intranasally inoculated with the SARS‑CoV‑2 virus, Isolate B strain and hCoV-19/Russia/SP48-1226/2020 strain (abbreviated name U-2), at a dose of 5.0 lg PFU. Using flow cytometry, the levels of 21 populations/subpopulations of mononuclear cells in the peripheral blood of animals were determined before experimental infection with the pathogen and on day 14 after infection. SARS‑CoV‑2 coronavirus RNA was assessed using real-time polymerase chain reaction. Determination of the titer of virus-neutralizing antibodies to the SARS‑CoV‑2 virus in the blood sera of animals was conducted through neutralization test evaluating the ability to suppress negative colonies.Results and discussion. Infection with Isolate B strain culture has led to an increase in the relative content of total T-lymphocytes (p˂0.2), cytotoxic T-lymphocytes (p˂0.1), as well as monocytes expressing the early activation marker CD25 (p˂0.2). The decrease in levels has been observed for total B-lymphocytes (p˂0.2) and T-helper cells (p˂0.1). Infection with the U-2 strain culture revealed an increase in the relative content of monocytes expressing the early activation marker CD25 (p˂0.2). Thus, for the first time in the Russian Federation, flow cytometry was used to study the cellular immunity of rhesus monkeys before and after experimental infection with the SARS‑CoV‑2 virus. The obtained information can be used for studying the pathogenesis of SARS‑CoV‑2 infection, course, and outcome of the disease, and developing strategies for vaccination and treatment

    Значение герминальной BRCA-мутации при формировании опухолевого микроокружения Эффективность PARP-ингибирования в поздней линии терапии метастатического кастрационно-резистентного рака предстательной железы

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    Metastatic castration-resistant prostate cancer is a difficult problem for a clinical oncologist. In addition, mutations in genes of homologous DNA recombination, including BRCA1/2, suggest an aggressive behavior and therapy resistance. Treatment options for such patients were significantly limited until new drugs - PARP inhibitors have been registered. Nevertheless, there is evidence that BRCA1/2 gene mutations are associated with increased mutational load, neoepitopes formation, increased number of tumor-infiltrating lymphocytes and a response to the immune response checkpoints blockade. Studies have shown that BRCA2-mutated prostate cancer demonstrates high level of immune cells infiltration compared to tumors without mutation, in particular with respect to CD4+, CD8+ and FOXP3+ T-lymphocytes. It should be noted that studies have shown a tendency of CD8+ T-lymphocytes/FOXP3+ T-cells ratio decreasing in BRCA2-mutated tumors. Thus, the mutational status of BRCA2 presumably forms the immune phenotype of prostate cancer with an increase of intratumoral immune cells, but with immunosuppressive properties. At the same time, the use of immune checkpoint blockers in advanced prostate cancer has been unsuccessful in terms of overall survival. Despite the fact that immune checkpoint blocker's efficacy is often associated with a high intracellular CD4+ and CD8+ T lymphocytes, their presence is clearly insufficient for response. Studies showed that PARP inhibitors effect tumor microenvironment significantly. Anti-PD-1/PD-L1 combination with PARP inhibitors is being actively studied due to their properties of modulating the tumor microenvironment. Thus, future immunooncological strategies for primary prostate cancer therapy may include not only an increase in mutational load, but also an impact on the immunosuppressive microenvironment. The article presents clinical cases of 3 brothers, carriers of the germinal BRCA2 c.9371A>T mutation, suffering from prostate cancer with a burdened family history. The disease development under standard therapies was studied and markers of the tumor microenvironment were immunohistochemically evaluated. PARP inhibitor Olaparib efficacy in prostate cancer of older brother in late-line therapy for metastatic castration-resistant disease was analyzed.Метастатический кастрационно-резистентный рак предстательной железы является сложной проблемой для клинического онколога. Кроме этого, наличие мутации в генах гомологичной рекомбинации ДНК, в том числе BRCA1/2, предполагает агрессивное течение и резистентность к проводимой терапии. До регистрации новой группы препаратов - PARP-ингибиторов - опции лечения таких больных были существенно ограниченны. Тем не менее есть данные о том, что мутации генов BRCA1/2 связаны с повышенной мутационной нагрузкой, образованием неоэпитопов, увеличением количества инфильтрирующих опухоль лимфоцитов и ответом на блокаду контрольных точек иммунного ответа. В исследованиях показано, что BRCA2-мутированный рак предстательной железы обладает высоким уровнем инфильтрации иммунными клетками по сравнению с опухолями без мутации, в частности в отношении Т-лимфоцитов, экспрессирующих CD4, CD8 и FOXP3. Следует отметить, что в исследованиях наблюдалась тенденция к снижению отношения CD8+-Т-лимфоцитов к FOXP3+-Т-клеткам в BRCA2-мутированных опухолях. Таким образом, мутационный статус BRCA2 предположительно формирует иммунный фенотип рака предстательной железы с увеличением количества интратуморальных иммунных клеток, но с иммуносупрессивными свойствами. При этом использование блокаторов контрольных точек иммунитета при распространенном раке предстательной железы до сих пор было в значительной степени безуспешным в отношении показателей общей выживаемости пациентов. Несмотря на то что эффективность блокаторов контрольных точек иммунитета зачастую связана с высоким содержанием внутриопухолевых CD4+- и CD8+-Т-лимфоцитов, их присутствия явно недостаточно для ответа. Как показано в исследованиях, ингибиторы PARP способны оказывать существенное влияние на микроокружение опухоли. Активно изучается комбинация анти-PD-VPD-Lt с ингибиторами PARP за счет их свойств модулирования микроокружения опухоли. Таким образом, будущие онкоиммунологические стратегии первичной терапии рака предстательной железы могут включать не только повышение мутационной нагрузки, но и воздействие на иммуносупрессивное микроокружение. В статье представлены случаи развития рака предстательной железы у 3 братьев, носителей герминальной мутации гена BRCA2 c.9371A>T с отягощенным семейным анамнезом. Изучено клиническое течение заболевания при применении стандартных методов терапии, иммуногистохимически оценены маркеры микроокружения опухоли. Проанализирована эффективность использования PARP-ингибитора олапариба у одного из братьев в поздней линии терапии при метастатическом кастрационно-резистентном заболевании
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