40 research outputs found
Recommended from our members
Comparison of the mRNA expression profile of B‐cell receptor components in normal CD5‐high B‐lymphocytes and chronic lymphocytic leukemia: a key role of ZAP70
Abstract The B‐cell receptor (BCR) signaling pathway is of great importance for B‐cell survival and proliferation. The BCR expressed on malignant B‐CLL cells contributes to the disease pathogenesis, and its signaling pathway is currently the target of several therapeutic strategies. Although various BCR alterations have been described in B‐CLL at the protein level, the mRNA expression levels of tyrosine kinases in B‐CLL compared to that in normal CD5‐high and CD5‐low B‐lymphocytes remain unknown. In the current study, we measured the mRNA expression levels of CD79A, CD79B, LYN, SYK, SHP1, and ZAP70 in purified populations of CD5‐high B‐CLL cells, CD5‐low B‐cells from the peripheral blood of healthy donors, and CD5‐high B‐cells from human tonsils. Here, we report a clear separation in the B‐CLL dataset between the ZAP70‐high and ZAP70‐low subgroups. Each subgroup has a unique expression profile of BCR signaling components that might reflect the functional status of the BCR signaling pathway. Moreover, the ZAP70‐low subgroup does not resemble either CD5‐high B‐lymphocytes from the tonsils or CD5‐low lymphocytes from PBMC (P < 0.05). We also show that ZAP70 is the only gene that is differentially expressed in CD5‐high and CD5‐low normal B‐lymphocytes, confirming the key role of Zap‐70 tyrosine kinase in BCR signaling alterations in B‐CLL
University language education: Lessons of forced transition to teaching online
Introduction. The unexpected transition to online teaching in spring 2020 resulted in educational institutions differently equipped in terms of technology, methodology and academic staff preparedness. Moreover, educational institutions faced with a totally new working environment. One may assume that during the pandemic, education systems of most countries crossed the Rubicon, and now there is no going back. What learning and teaching will be like in the future depends, to a large extent, on the lessons the teaching community will learn. The aim of the research was to find out how successful the emergency transition to teaching foreign languages online was and to identify technological resources necessary to maintain the quality of foreign language teaching and learning in different educational formats. Methodology and research methods. The research was carried out in line with the learner- centered activity approach and principles of distant teaching and learning; it also included analysis of online teaching practices across the world before and during the COVID-19 pandemic. The research data was collected via three surveys conducted (with Google forms) among foreign language teachers of MGIMO University (1329 questionnaires) in April, June and September, 2020; 15 heads of foreign language(s) departments (July 2020), and 201 MGIMO students (September 2020). The data was analysed using IBM SPSS Statistics: correlation and cross tabulation analyses, linear regression analysis, and ANOVA. Results. In the course of the research, the correlations between class activities, selfstudy assignments, forms of assessment, and students’ engagement in learning have been established; as well as the fact that individual approach in teaching has a positive effect on students’ activity, responsibility and academic independence. Furthermore, the problems in online teaching have been identified: classes were not communicative enough, nor teaching sufficiently individualised; besides, the quality of assessment declined with the transition to online learning format. Scientific novelty. An attempt has been made to evaluate the experience of remote teaching foreign languages at university level after the emergency shift to online learning format, and to find out its potential for maintaining (and, in prospect, improving) the quality of language education. Practical significance. Class activities, self-study assignments and forms of testing found the most effective in this research can be of use to foreign language teachers working online. The need to provide individual trajectories for students to develop communicative competence in a foreign language has been established, which is important for course, programme and teaching materials designers.Введение. Незапланированный переход к онлайн обучению весной 2020 года привел к тому, что учебные заведения с разным уровнем технической, методической и кадровой готовности мгновенно оказались в совершенно новых условиях работы. Можно предположить, что в это время система образования во всех странах, затронутых пандемией, прошла некую точку невозврата – таким как раньше процесс обучения не будет. Каким он будет, во многом зависит от того, какие уроки педагогическое сообщество извлечет из этого опыта. Цель исследования – определение степени успешности опыта вынужденного перехода в онлайн и выявление методических ресурсов, необходимых для сохранения качества языковой подготовки в разных форматах обучения. Методология, методы и методики. Исследование проводилось с опорой на личностно-деятельностный подход в обучении, принципы дистанционного обучения и включало анализ практического опыта обучения онлайн в разных странах до и во время пандемии COVID-19. Для сбора эмпирического материала использовался метод анкетирования. Участие в опросе приняли преподаватели кафедр иностранных языков МГИМО (общее число полученных анкет 1 329), заведующие кафедрами (15 анкет) и выборочно студенты (201 анкета). Опрос проводился в три этапа – в апреле, июне и сентябре 2020 года. Для статистической обработки данных в программе IBM SPSS Statistics применялись корреляционный анализ, кросстабуляционный анализ, линейный регрессионный анализ и однофакторный дисперсионный анализ (ANOVA). Результаты. В ходе исследования, во-первых, установлены корреляционные связи между видами аудиторной и самостоятельной работы студентов, формами контроля и активностью, сознательностью и самостоятельностью студентов; доказано, что на эти показатели положительно влияет индивидуализация обучения. Во-вторых, выявлены проблемные зоны в условиях обучения онлайн: недостаточно высокая степень коммуникативности и индивидуализации обучения, а также снижение качества контроля результатов обучения. Научная новизна. Предпринята попытка оценить опыт форс-мажорного перехода к удаленному обучению иностранным языкам и определить его потенциал для сохранения (и, в перспективе, повышения) качества языковой подготовки в вузе. Практическая значимость. Выявлены наиболее эффективные виды заданий для аудиторной и самостоятельной работы студентов и формы проверки качества усвоения в формате онлайн, что может помочь преподавателям при работе в этом формате. Обоснована необходимость предусматривать индивидуальные траектории овладения иноязычной коммуникативной компетенцией, что важно для разработчиков курсов, программ и учебных материалов
Tuberculosis in HIV-infected children in Europe, Thailand and Brazil: paediatric TB-HIV EuroCoord study
SETTING: Centres participating in the Paediatric European Network for Treatment of AIDS (PENTA), including Thailand and Brazil.
OBJECTIVE: To describe the incidence, presentation, treatment and treatment outcomes of tuberculosis (TB) in human immunodeficiency virus (HIV) infected children.
DESIGN: Observational study of TB diagnosed in HIV-infected children in 2011–2013.
RESULTS: Of 4265 children aged <16 years, 127 (3%) were diagnosed with TB: 6 (5%) in Western Europe, 80 (63%) in Eastern Europe, 27 (21%) in Thailand and 14 (11%) in Brazil, with estimated TB incidence rates of respectively 239, 982, 1633 and 2551 per 100 000 person-years (py). The majority (94%) had acquired HIV perinatally. The median age at TB diagnosis was 6.8 years (interquartile range 3.0–11.5). Over half (52%) had advanced/severe World Health Organization stage immunodeficiency; 67 (53%) were not on antiretroviral therapy (ART) at TB diagnosis. Preventive anti-tuberculosis treatment was given to 23% (n = 23) of 102 children diagnosed with HIV before TB. Eleven children had unfavourable TB outcomes: 4 died, 5 did not complete treatment, 1 had recurrent TB and 1 had an unknown outcome. In univariable analysis, previous diagnosis of acquired immune-deficiency syndrome, not being virologically suppressed on ART at TB diagnosis and region (Brazil) were significantly associated with unfavourable TB outcomes.
CONCLUSION: Most TB cases were from countries with high TB prevalence. The majority (91%) had favourable outcomes. Universal ART and TB prophylaxis may reduce missed opportunities for TB prevention
The effect of silver-containing sorbent on red blood cells during hemosorption: an <i>in vitro</i> study
The aim of the study was to investigate the influence of the original porous silver–containing sorbent on the morphofunctional parameters of red blood cells during in vitro hemoperfusion. Material and methods. Donor blood was perfused through glass columns filled with a sorbent based on porous aluminum oxide, polydimethylsiloxane and silver nanoclusters and a sorbent without silver. The effect of a silver-containing sorbent on the change in morphofunctional parameters of red blood cells after perfusion through sorbents was determined by scanning flow cytometry. Results and their discussion. Due to the uniformity of the distribution of silver (0.1 %) over the sorbent granules, the parameters of the porous structure – the specific surface area and pore volume – practically do not change compared to the sorbent without silver. Morphological parameters of original donor blood and after hemoperfusion are within the norm. The functional parameters are also normal, although the introduction of silver in to the sorbent slightly increases the number of active band 3 (B3) proteins on erythrocyte membranes, both in comparison with the donor red cell mass as a control and in comparison with the sorbent without silver. There is also an increase in the ultimate extensibility of the erythrocyte membrane compared to the original blood (2.2 times) and the sorbent without silver (1.4 times). Conclusions. A sorbent modified with silver and a sorbent without silver does not have a damaging toxic effect on the morphofunctional parameters of blood under perfusion conditions. The mechanisms affecting the indicators of the ultimate extensibility of the erythrocyte membrane after blood perfusion through a silver-containing sorbent require further research
ЭКСПРЕССИЯ ВИМЕНТИНА В КУЛЬТУРАХ КЛЕТОК ЭПИТЕЛИАЛЬНЫХ ОПУХОЛЕЙ ЧЕЛОВЕКА
Background. Cell cultures used as a models in studies of epithelial tumors, are obtained not only from solid tumors, but also from extracellular fluids. It is known that dissemination of ovarian cancer in the peritoneum and further growth of tumor cells in ascetic liquid is accompanied with the activation of epithelial-mesenchymal transition, and, therefore, cell cultures derived from extracellular fluids can have a distinct molecular phenotype from primary tumors.Objective: evaluation the “persistence” of epithelial phenotype in breast and ovarian cancer cell cultures.Materials and methods. The cells obtained from pleural fluid (MCF-7, T-47D), colostrum (HBL-100), solid tumors (BT-474, HCC1937) of patients with breast cancer and ascitic fluid (SCOV- 3) of patients with ovarian cancer. The expression of cytokeratins and vimentin was evaluated using a quantitative immunofluorescence method associated with flow cytometry.Results. Vimentin expression in cells derived from extracellular fluids was not changed (line HBL-100), slightly decreased (SCOV-3 cells), or even was lost (MCF-7 and T-47D cells). HCC1937 cells obtained from solid tumor with expected low expression of vimentin acquired a molecular phenotype with a high expression of this mesenchymal marker. In breast cancer cells BT-474 derived from solid tumor a “persistence” of epithelial phenotype was discovered.Conclusion. Quantitative assessment of the de novo expression of mesenchymal protein vimentin showed that the tumor phenotype within the organizm is not always realized in cells adapted to growth in culture, and is not always «strictly» epithelial, and this evidence must be considered with different kinds of molecular studies of epithelial cells in vitro.Введение. Клеточные культуры, используемые в качестве модельных при исследовании опухолей эпителиального происхождения, получают не только из сóлидных новообразований, но и из экстрацеллюлярных жидкостей. Известно, что диссеминация рака яичников по брюшине и дальнейший рост опухолевых клеток в асцитической жидкости сопровождаются активацией в них эпителиально-мезенхимального перехода и, следовательно, клеточные культуры, полученные из экстрацеллюлярных жидкостей, могут иметь молекулярный фенотип, отличный от первичного новообразования. Цель исследования – оценка «сохранности» эпителиального фенотипа клеточных линий рака молочной железы и яичников.Материалы и методы. В работе использованы клеточные линии, полученные из плевральной жидкости (MCF-7, T-47D), молозива (HBL-100), сóлидного опухолевого узла (BT-474, HCC1937) больных раком молочной железы и асцитической жидкости (SCOV-3) больной раком яичников. Экспрессию цитокератинов и виментина оценивали с помощью количественного иммунофлуоресцентного метода, ассоциированного с проточной цитофлуориметрией.Результаты. Высокий уровень виментина в клетках, полученных из экстрацеллюлярных жидкостей, сохранялся (линия HBL-100), умеренно снижался (клетки SCOV-3) и даже утрачивался (клетки MCF-7 и T-47D). Клетки линии HCC1937, полученные из сóлидного узла с ожидаемо низкой экспрессией виментина, при росте в культуре приобрели молекулярный фенотип с высоким уровнем экспрессии этого мезенхимального маркера. В клетках рака молочной железы BT-474, полученных из сóлидного новообразования, по показателю экспрессии виментина обнаружено сохранение эпителиального фенотипа при росте in vitro.Заключение. Оценка параметров экспрессии de novo мезенхимального белка виментина показала, что фенотип опухоли в организме не всегда реализуется в клетках, адаптированных к росту в культуре, и не всегда является «строго» эпителиальным, что необходимо учитывать при разного рода молекулярных исследованиях эпителиальных клеток in vitro
Изучение фармакокинетического профиля лекарственного препарата Гидазепам®, таблетки, 50 мг в исследовании биоэквивалентности
Aim. The primary aim of this study was to evaluate the pharmacokinetic parameters and confirm the bioequivalence of drugs containing gidazepam, namely Gidazepam® (Valenta Pharm, Russia) and Gidazepam VIC (VIVA Pharm, Republic of Kazakhstan), after a single administration of 1 tablet (50 mg) to healthy volunteers under fasting conditions. The secondary aim was a comparative analysis of safety profiles (adverse events) after a single administration of the studied drugs.Materials and methods. An open, randomized, crossover, two-period comparative study of pharmacokinetics and bioequivalence with adaptive design was conducted in healthy volunteers. Blood sampling was performed 15 minutes before and 20 min, 40 min, 1 h, 2 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 6 h, 8 h, 12 h, 24 h, 48 h, and 72 h after drug administration. High-performance liquid chromatography-tandem mass spectrometry was used for the evaluation of gidazepam and its metabolite (desalkylgidazepam) concentration with the subsequent calculation of pharmacokinetic parameters.Results. From both formulations, gidazepam was quickly absorbed and biotransformed into an active metabolite. Studied drugs had similar pharmacokinetic profiles, as 90% confidence intervals for the ratio of geometric means for Cmax and AUC(0-72) were within the bioequivalence acceptance range of 80.00–125.00 %. No adverse events were recorded as a result of clinical, laboratory or instrument evaluations during the study.Conclusion. Study drugs are considered bioequivalent and show comparable tolerability after a single administration under fasting conditions.Цель исследования. Изучение фармакокинетики и подтверждение биоэквивалентности препаратов, содержащих гидазепам: Гидазепам® (АО «Валента Фарм», Россия) и Гидазепам VIC (ТОО «ВИВА ФАРМ», Республика Казахстан) при однократном приёме 1 таблетки (50 мг) здоровыми добровольцами натощак. Дополнительной целью исследования являлся сравнительный анализ данных о нежелательных явлениях при однократном приёме изучаемых препаратов.Материал и методы. Проведено открытое, рандомизированное, перекрёстное, двухпериодное с адаптивным дизайном исследование сравнительной фармакокинетики и биоэквивалентности с участием здоровых добровольцев. Отбор образцов крови осуществляли за 15 мин до приёма и через 20 мин, 40 мин, 1 ч, 2 ч, 3 ч, 3,5 ч, 4 ч, 4,5 ч, 5 ч, 6 ч, 8 ч, 12 ч, 24 ч, 48 ч и 72 ч после приёма лекарственных препаратов. С помощью метода высокоэффективной жидкостной хроматографии с тандемной масс-спектрометрией определяли концентрацию гидазепама и его метаболита (дезалкилгидазепама) для последующего расчёта фармакокинетических показателей.Результаты исследования. Гидазепам в составе двух сравниваемых лекарственных препаратов характеризовался быстрой абсорбцией и биотрансформацией с образованием активного метаболита. Препараты исследования обладали эквивалентным фармакокинетическим профилем, поскольку 90 % доверительные интервалы для отношения геометрических средних величин параметров Cmax и AUC(0–72) не выходили за установленные пределы 80,00–125,00 %. По данным клиниколабораторного и инструментального наблюдения за время проведения исследования у добровольцев не было зарегистрировано ни одного нежелательного явления.Заключение. Сравниваемые препараты являются биоэквивалентными и демонстрируют одинаковый профиль переносимости при однократном приёме натощак
Иммуноферментные системы и набор реагентов для определения бацитрацина в пищевых продуктах
Two test-systems for a direct and an indirect enzyme-linked immunosorbent assay (ELISA) of peptide antibiotic bacitracin (BC) were developed and studied. For the both systems, polyclonal antibodies were obtained by immunizing rabbits with a conjugate of BC with keyhole limpet hemocyanine synthesized using reaction between the peptide and the high molecular weight protein in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The product of BC linking to thyroglobulin which was activated with EDC and N-hydroxysulfosuccinimide served as conjugated antigen on a solid phase in the indirect ELISA. For the direct ELISA, the antibodies against BC were immunochemically immobilized onto microplate surface, while the liquid phase contained a conjugate of BC with horseradish peroxidase. This conjugate was obtained by successive reactions of antibiotic amino groups coupling to periodate oxidized carbohydrate chains of enzyme and the reducting of formed Shiff’s base with sodium borohydride. Conjugated antigens binding to anti-BC antibodies provided maximum colorimetric signals of 2.0 and 1.2 optical units for the direct and indirect ELISA, respectively, and depended on BC content in the liquid phase. Antibiotic concentration that caused the inhibition of binding by 50 % was 2.6 ng/ml in the direct ELISA and 10.0 ng/ml in the indirect ELISA. The simple and sensitive direct ELISA system was used as a prototype of the finished reagent kit and a method for measurements with technical-analytical parameters and metrological characteristics allowing the determination of BC residues in a variety of foods including 14 items in a concentration range of 9.0 to 405.0 pg/kg with proper accuracy and precision.Разработаны тест-системы для непрямого и прямого иммуноферментного анализа (ИФА) пептидного антибиотика бацитрацина (Бц). Поликлональные антитела для обеих тест-систем получены иммунизацией кроликов конъюгатом Бц и гемоцианина улитки, который синтезировали взаимодействием пептида с белком в присутствии 1-этил-3-(3-диметиламинопропил)-карбодиимида (EDC). В системе непрямого ИФА твердофазным конъюгированным антигеном служил продукт присоединения Бц к тироглобулину, предварительно активированному EDC и N-гидроксисульфосукцинимидом. Для прямого ИФА на поверхности лунок микропланшета были иммунохимически иммобилизованы антитела к Бц, а жидкая фаза содержала конъюгат Бц с пероксидазой из корней хрена, полученный путем последовательных реакций присоединения аминогрупп Бц к окисленной периодатом углеводной части фермента и восстановления образовавшегося основания Шиффа борогидридом натрия. В системах прямого ИФА и непрямого ИФА связывание конъюгированных антигенов с антителами к Бц обусловливало максимальные колориметрические сигналы около 2,0 и 1,2 единиц оптической плотности соответственно и зависело от содержания Бц в жидкой фазе. При этом концентрации антибиотика, вызывающие ингибирование связывания на 50 %, составили 2,6 нг/мл в прямом ИФА и 10,0 нг/мл в непрямом ИФА. Простая и чувствительная система прямого ИФА послужила прототипом для создания готового набора реагентов и методики выполнения измерений, технико-аналитические параметры и метрологические характеристики которых позволяют определять остаточные количества Бц в пищевой продукции животного происхождения расширенного перечня, включающего 14 наименований, в диапазоне от 9,0 до 405,0 мкг/кг с надлежащей правильностью и точностью
Real-time measurement of relative sensor position changes by ultrasonic signal evaluation
Ultrasonic testing is considered to be one of the most commonly applied nondestructive testing techniques for flaw detection and material characterization. Traditional Nondestructive Testing (NDT) provides detection of material discontinuities that may cause failure within the designed lifetime of a part or component. In addition, Quantitative Nondestructive Testing (QNDT) provides means to obtain required information about type, size and location of deficiencies to the integrity of the inspected structure and further use under specific, given load conditions. The "Acoustic Mouse" technique has been developed as a tool for manual ultrasonic inspection to provide test results that can be evaluated quantitatively. The ultrasonic data are processed by real-time variation methods to extract position information from backscattered acoustic noise and geometric scatter signals in the inspection volume. The position and positional changes of the "Acoustic Mouse" sensor (transducer) are determined by the sequential analysis of ultrasonic data (highresolution sector-scans), which are acquired and reconstructed using the Sampling Phased Array technique. The results of first experiments conducted with linear scanning and intentional lift-offs demonstrate sufficient accuracy in position measurements
Models of dependence of the quantity of the <i>Streptococcus pneumoniae biomass</i> and his capsular polysaccharide from the composition of the feeding environment
Aim.The development of a semi-synthetic nutrient medium that provides the maximum amount of capsular polysaccharide (CPS). Materials and methods. We used the strain 521 of S. pneumoniae serotype 23F. Cultivation was carried out in test tubes with 10 ml of polysynthetic nutrient medium of a specific composition. The amount of polysaccharide in the samples was determined using rocket immunoelectrophoresis. Building models and comparing the effects of various components was carried out according to the methodology specified in the tutorial. The calculation of the coefficients of the equation and the assessment of the adequacy of the equations themselves was carried out using RStudio version 1.0.153. Results. As a result of a series of experiments, the coefficients of the regression equations were calculated, their significance was evaluated, and models of dependence of biomass production and CPS were constructed depending on the composition of the nutrient medium. To solve the problem, an experiment was carried out according to the Box-Wilson method. The peptone and glucose concentrations were selected as optimized parameters. The step size ΔSi in the increasing gradient direction was calculated based on the coefficients of the regression equation. At the same time, the exact nature of the dependence was determined. The optimal calculated concentrations of peptone and glucose, at which the formation of CPS is maximum, are 32.6 and 12.1 g/l, respectively. In this case, the forecast yield of the polysaccharide is 239 mg/l. Conclusion. Using the method of fractional factorial experiment, models of the dependence of the biomass amount of S. pneumoniae and its capsular polysaccharide on the composition of the nutrient medium were obtained. The optimal concentrations of the components of the medium were found, which make it possible to increase the level of biomass formation by 10% compared to the standard formulas, and the CPS — by 1.5—2 times