Functional activities of DNA-guided and RNA-guided bacterial Argonaute proteins

Specific targeting of nucleic acids by Argonaute (Ago) proteins lies at the heart of RNA interference. Eukaryotic Ago’s bind small RNAs and use them as guides for target RNA recognition and cleavage. Argonaute proteins are also found in bacterial and archaeal genomes where their roles remain unclear. Structural and biochemical studies of a few prokaryotic Ago proteins showed that they can function as endonucleases in vitro and may provide cell defense against foreign genetic elements in vivo. However, most prokaryotic Ago’s are predicted to lack endonuclease activity; they also often have unusual domain architectures and are associated in the same operons with putative nucleases or helicases. In this study, we focused on prokaryotic Ago’s from several cultivable bacterial species. We showed that although eukaryotic Ago’s work only with RNA, prokaryotic proteins included in our analysis can use either RNA or DNA guides to recognize DNA targets. To define the specificity of bacterial Ago’s we expressed them in Escherichia coli and analyzed associated short nucleic acids. Furthermore, we tested nucleolytic activity of three proteins in vitro using different guide and target molecules, and also measured the affinity of Ago’s to guides and targets. The slicer activity of Ago’s is known to depend on four conserved amino acid residues in the catalytic center. We showed that, in agreement with bioinformatic predictions, two of the three proteins possess the endonuclease activity. Our results indicate that bacterial Ago proteins can cleave target nucleic acids with high specificity in vitro and can function in the heterologous E. coli system in vivo. These properties likely underlie the process of DNA/RNA interference in bacterial cells and may promote horizontal transfer of the Ago genes

The rational conducting of pregnancy and kinds with the immunological conflikt (experience of 35-years work)

Purpose: To estimate efficiency of work of the specialized reception of pregnant with an immunological conflict.Materials and Methods: The analysis of flow of pregnancy is conducted, births, ends for a fruit in 5- ti clinical groups. A dynamic supervision was conducted, a title was determined groups and anti-rezusnykh antibodies, ULTRASONIC, dopplerometriya fruit.Results: In all 21659 children borned in all clinical groups, at the 1377 (6,4%) new-born was GB is diagnosed.Summary: The got results confirmed efficiency of work of the specialized reception, that allowed to reduce morbidity ot gemoliticheskoy illness in 6 times

Plasmon effect on triplet-singlet energy transfer in the dye-doped Langmuir-Blodgett films

The effect of silver plasmonic nanoparticles on triplet-singlet energy transfer in the donor-acceptor pair of organic dyes was studied. Layered dye films were prepared on the surface of glass and island silver films using the Langmuir-Blodgett method. Amphiphilic analogs of Rose bengal and polymethine dye were used as donor and acceptor of energy. A polymer monolayer was deposited between monolayers of donor and acceptor molecules to exclude the competing triplet-triplet energy transfer. The spectra of delayed fluorescence and phosphorescence of donor-acceptor films and the delayed luminescence lifetime of donor in these films have been measured. It is shown that a threefold increase in the fluorescence intensity and a twofold increase in the donor phosphorescence intensity are observed on silver island films. The successful triplet-singlet energy transfer is evidenced by both the quenching of donor centers and appearance of sensitized delayed fluorescence of the acceptor with the duration close to the donor triplet lifetime. In the presence of silver nanoparticles, in addition to enhancement in the intensity of the donor emission, an increase in the efficiency of tripletsinglet energy transfer was observed. The obtained results can be used in various optical devices

The components of clinical interaction ethics

Ethical norms are traditionally inseparable from medical work as such and are an unconditional part of the general idea of medicine and doctorhood. However, the structure of medical ethics is ambiguous and complex. It includes the ways in which ethically loaded decisions are made, the categories of ethically loaded decisions themselves and the good/bad dichotomy, as well as cultural context that defines these categories. The psychological component also plays a role: mental state of a patient, a doctor, as well as verbal and nonverbal communication. Finally, the legal framework is imperatively introduced into the doctor-patient relationship, setting norms regardless of the nuances of interpersonal interaction. This article discusses the most important and explicit components of an ethical relationship in helping, and also proposes as a universal solution the ethics of virtue neither as an instrumental, but an essential approach

New quality criteria for fresh frozen plasma

Objective: development of new quality criteria for fresh frozen plasma. Matherials and methods: at diff erent times of storage of fresh frozen plasma harvested standardly and from the donors aft er Biolan exposure, the parameters of the kallikrein-kinin system were determined: the activity of kallikrein, the inhibitory activity of the α1 -proteinase inhibitor, α2 -macroglobulin, the total arginine-esterase activity and the level of prekallikrein. Results: during the quarantine process of fresh frozen plasma, prepared in a standard way, the processes of proteolysis activation is noticed already by 10th day from the beginning of FFP storage, and the preparation of donors for the blood donation with help of the biolan adaptogen provides better preservation of the components of the kallikrein-kinin system. Conclusions: analysis of the main components of the kallikrein-kinin system can be used as an additional criterion of the quality of fresh frozen plasma before the transfusion procedure

Анализ эффективности тромбопрофилактики у беременных с мезенхимальной дисплазией

the analysis of the effectiveness of thromboprophylaxis among pregnant women with mesenchymal dysplasia was carried out. It was concluded that it reduces the risk of thrombohemorrhagic complications and accordingly the economic costs of medical care.проведен анализ эффективности тромбопрофилактики у беременных с мезенхимальной дисплазией, при использовании которой во время беременности у таких пациенток снижается риск возникновения тромбогеморрагических осложнений и, следовательно, уменьшаются финансовые затраты

Исследование влияния генетического варианта c.470T>C в гене CHEK2 на повышение риска развития рака молочной железы у населения Российской Федерации

Introduction. Currently, there are conflicting data regarding the effect of the c.470T> C germline mutation in the CHEK2 gene on increasing the risk of breast cancer (BC), so it is necessary to conduct research on large samples of patients, including in the Russian population, in order to analyze the contribution of this mutation to the risk of cancer developing.The aim of the study was to determine the frequency of occurrence of the genetic variant c.470Т>С in the CHEK2 gene in the Russian population in patients with BC and patients with benign breast diseases (BBD) to assess the possible effect of this deoxyribonucleic acid damage on the likelihood of cancer occurrence.Materials and methods. The study included 2,787 patients with BC and 1,004 patients with BBD who underwent examination and treatment at the Russian Scientific Center of Roentgenoradiology of the Ministry of the Russian Federation from 2010 to 2018. Molecular genetic study was carried out by real-time polymerase chain reaction to determine the characteristic of the Russian population hereditary genetic variant c.470Т>С in the CHEK2 gene using a diagnostic panel that allows to determine three germline mutations: c.1100delC, c.444+1G>A and c.470Т>С in the CHEK2 gene.Results. In patients with BC the frequency of the mutation c.470T>C in the CHEK2 gene was 3.8 %, in patients with BBD this mutation was detected in 4.7 % of cases. The frequency of the genetic variant c.470T>C in high-risk groups was: 5.1 % – for BC patients with clinical signs of hereditary disease and 4.9 % – for patients with BBD with a family history of cancer. There were no statistically significant differences between the frequency of the mutation c.470T>C in the general groups of BC patients and patients with BBD and the corresponding frequency in the high-risk groups, as well as in the groups of BC patients and patients with BBD (p >0.05).Conclusion. The results of this study indicate the probable absence of a relationship between the presence of the mutation c.470Т>С in the CHEK2 gene and an increased risk of BC.Введение. В настоящее время имеются противоречивые данные относительно влияния герминальной мутации с.470Т>С в гене CHEK2 на повышение риска возникновения рака молочной железы (РМЖ), поэтому необходимы исследования на больших выборках больных, в том числе в российской популяции, в целях анализа вклада данной мутации в риск развития онкологического заболевания.Цель исследования – определение частоты встречаемости генетического варианта с.470Т>С в гене CHEK2 в российской популяции у больных РМЖ и пациенток с доброкачественными заболеваниями молочной железы (ДЗМЖ) для  оценки возможного влияния данного повреждения дезоксирибонуклеиновой кислоты на вероятность возникновения онкологического заболевания. Материалы и методы. В исследование были включены 2787 больных РМЖ и 1004 пациентки с ДЗМЖ, проходившие обследование и лечение в ФГБУ «Российский научный центр рентгенорадиологии» Минздрава России с 2010 по 2018 г. Молекулярно-генетическое исследование для определения характерного для российской популяции наследственного генетического варианта с.470Т>С в гене CHEK2 было проведено методом полимеразной цепной реакции в режиме реального времени с использованием диагностической панели, позволяющей определять три герминальные мутации: с.1100delC, c.444+1G>A и с.470Т>С в гене CHEK2.Результаты. У больных с диагнозом РМЖ частота мутации c.470T>C в гене CHEK2 составила 3,8 %, у пациенток с ДЗМЖ данная мутация выявлена в 4,7 % случаев. Частота генетического варианта c.470T>C в группах повышенного риска составила 5,1 % для больных РМЖ с клиническими признаками наследственного заболевания и 4,9 % для  пациенток с  ДЗМЖ, имеющих онкологически отягощенный семейный анамнез. Статистически значимых различий между частотой мутации c.470T>C в общих группах больных РМЖ и пациенток с ДЗМЖ и  соответствующей частотой в  группах повышенного риска, а  также в  группах больных РМЖ и  пациенток с ДЗМЖ не установлено (p >0,05).Заключение. Результаты проведенного исследования свидетельствуют о вероятном отсутствии связи между наличием мутации с.470Т>С в гене CHEK2 и повышением риска развития РМЖ

MOLECULAR-GENETIC CHARACTERISTICS OF PRIMARY TUMOR AND METASTATIC LYMPHATIC NODES IN BREAST CANCER

The purpose of systemic treatment in patients with breast cancer is based largely on the molecular characteristics of the primary tumor, but many clinical recommendations suggest also the study of metastatic nodes with an assessment of their receptor status (estrogen receptor ER, progesterone receptor RP, human epidermal growth factor receptor 2 Her2/neu). This is due to the fact that according to numerous studies, the discrepancy between the status of the primary tumor and the secondary nodes can reach high rates: 3–54 % for ER, 5–78 % for RP, and 0–34 % for Her2/neu. At the same time, more and more data actively demonstrate the imperfection of immunohistochemical analysis and the need to study additional parameters to improve the quality of diagnosis of patients with breast cancer. Material and methods. A morphological and immunohistochemical study of the tumor tissue of the primary node and axillary lymph nodes was performed in 199 patients with breast cancer (T1-3N0-3M0) using standard methods, and RT-PCR was also studied with the expression of 24 genes. Results. The incidence of differences between the molecular phenotypes of the main tumor and metastatic axillary lymph nodes was 26 (26 %) of 99 cases. Most often, differences were noted in cases of breast cancer with luminal A type – 13 cases (50 %). According to the results of a comparative PCR analysis of tissue samples from the primary tumor and metastatic regional lymph nodes, only the expression of the CD68, ERSR1, GRB7 and MMD11 receptors was statistically significant. Conclusion. The results indicate the need for an integrated approach and additional methods for the diagnosis of breast cancer, which will undoubtedly improve the quality of planning and the effectiveness of systemic treatment in patients with breast cancer

ВЭЖХ определение, фармакокинетика и относительная биодоступность левофлоксацина производства ООО «ОЗОН», Россия

A simple, specific, sensitive and reproducible good method for quantitative determination of Levofloxacin in plasma using HPLC with UV-spectrophotometric detection. With this technique the pharmacokinetics and relative bioavailability of domestic generic of levofloxacin in 18 healthy volunteers after a single oral dose of 500 mg. Found that the drug being tested, levofloxacin (OOO «Ozone», Russia) is bioequivalent to the reference drugs Tavanic® («Sanofi Winthrop Industry», France).Описана простая, специфичная, чувствительная и хорошо воспроизводимая методика количественного определения левофлоксацина в плазме крови с применением высокоэффективной жидкостной хроматографии с УФ- спектрофотометрическим детектированием. С помощью настоящей методики изучена фармакокинетика и относительная биодоступность отечественного воспроизведённого препарата левофлоксацин у 18 здоровых добровольцев после однократного перорального приёма в дозе 500 мг. Установлено, что тестируемый препарат левофлоксацин (ООО «Озон», Россия) является биоэквивалентным препарату сравнения Таваник® («Санофи Винтроп Индустрия», Франция)

Исследование цитостатических и цитотоксических свойств модифицированных пептидных ингибиторов CDK4/6, функциональных аналогов p16INK4a (90-97)

Background. Application of mathematical modeling for search for biologically active molecules is currently a promising scientific approach. Application of numerical algorithms for optimization of peptide sequences and molecular dynamics allowed to obtain modified peptide sequences that are functional analogs of the sequence of natural inhibitor of cyclin-dependent kinase 4/6 p16INK4a.The study objective is to establish biological characteristics of peptide sequences of CDK 4/6 inhibitors obtained using mathematical modeling.Materials and methods. The studies were performed in vitro using tumor cell lines (MCF-7, А549, SKOV-3, НСТ116). Apoptosis level, cell distribution per cell cycle stages, changes in Bcl-2 expression, changes in the level of phosphorylated pRb under the effect of the studied molecules were investigated using flow cytometry. Proliferation dynamics of cell populations were studied using RTCA iCELLIgence biosensor technology.Results. Peptide sequences obtained using mathematical modeling decrease the level of phosphorylated pRb, Bcl-2 expression when applied to actively proliferating cells. These proteins serve as molecular targets for the cyclin-dependent kinase 4/6–cyclin D complex, and changes in pRb and Bcl-2 levels might indicate inhibition of complex formation. Consequently, decreased proliferative activity and increased apoptosis were observed. Effectiveness of the peptide sequences depended on their molecular structure and type of the used cell line. Two (2) of the studied modified peptide sequences have higher antiproliferative and proapoptotic effect on tumor cells than native p16INK4a (90-97) sequence.Conclusion. Application of mathematical modeling for search and development of functionally active molecules allowed to create peptide sequences with stronger cyclin-dependent kinase inhibitor effect than p16INK4a, the native inhibitor CDK4/6.Введение. Использование методов математического моделирования для поиска биологически активных молекул – перспективное направление современной науки. Применение численных алгоритмов для оптимизации пептидных последовательностей и методов молекулярной динамики позволило получить модифицированные пептидные последовательности, являющиеся функциональными аналогами последовательности естественного ингибитора циклиновой киназы 4/6 – p16INK4a.Цель исследования – определение биологических свойств пептидных последовательностей, ингибиторов CDK4/6, полученных с помощью методов математического моделирования.Материалы и методы. Исследования проведены в условиях in vitro на линиях опухолевых клеток (MCF-7, А549, SKOV-3, НСТ116). Методом проточной цитофлуориметрии были определены уровень апоптоза, распределение клеток по фазам клеточного цикла, изменение экспрессии белка Bcl-2, изменение уровня фосфорилированного pRb при воздействии на клетки исследуемых пептидных последовательностей. С помощью биосенсорной технологии RTCA iCELLIgence проведена оценка динамики пролиферации клеточных популяций.Результаты. Пептидные последовательности, полученные с помощью методов математического моделирования, при воздействии на активно пролиферирующие клетки вызывают снижение уровня фосфорилированного pRb, снижение экспрессии Bcl-2, которые являются молекулярными «мишенями» комплекса циклинзависимая киназа 4/6–циклин D, и изменение уровней pRb и Bcl-2 может свидетельствовать об ингибировании образования комплекса. Как следствие, наблюдались снижение пролиферативной активности и увеличение уровня апоптоза в клетках. Эффективность пептидных последовательностей зависела от молекулярной структуры, типа клеточной линии, на которую происходит воздействие. Показано, что 2 исследованные модифицированные пептидные последовательности оказывают на опухолевые клетки антипролиферативный и проапоптотический эффекты в большей степени, чем исходная последовательность p16INK4a (90-97).Заключение. Использование методов математического моделирования для поиска и разработки функционально активных молекул позволило создать пептидные последовательности, обладающие более выраженными свойствами ингибиторов циклиновых киназ, чем естественный ингибитор CDK4/6 – p16INK4a