Escherichia coli Strain – Super-Producer of Vibrio cholerae Hemolysin

Objective of this work was the cloning of Vibrio cholerae hlyA gene in a plasmid vector providing expression of foreign genes under the control of T5 promoter, and construction of E. coli strain – super-producer of Vibrio cholerae recombinant hemolysin. Materials and methods. V. cholerae о1 strain served as a DNA donor, pQE30 – as a vector plasmid. The gene was PCR-amplified, cloning was carried out by means of conventional methods, productivity of recombinants and localization of the required protein was determined based on the results of electrophoresis of cell lysates. Results and conclusions. A recombinant plasmid pHlyA, expressing the cloned hlyA gene of Vibrio cholerae El Tor under the control of T5 promoter after IPTG induction, has been constructed. Carrying this plasmid strain E. coli M15[pREP4]pHlyA is the super-producer of hemolysin: the content of the product in whole cell lysates is up to 13 %, and in inclusion bodies – up to 17 % of the total cell proteins. The product of the cloned gene, in spite of the absence of proteolytic processing and presence of the hexahistidine block (6His-tag) at its N-terminus, possesses hemolytic activity towards sheep erythrocytes. 6His-tag will provide for obtaining a purified preparation on specific sorbents with a view to create diagnosticums as well as to study the significance of hemolysin as a pathogenicity/persistence factor. The advantages of this producer are the high output of the required protein, inability of synthesis of any accessory biologically active substances, short-term period of biomass growing (4–6 h including induction) and possibility of culturing without sticking to the guidelines for work with the agents of particularly dangerous infections

Immunohistochemical evaluation of Ki-67, Cyclin D1 and β-catenin expression in the subtypes of triple negative breast cancer

Aim. To evaluate the expression levels of Ki-67 and cyclin D1 and β-catenin in the subtypes of triple negative breast cancer. Methods. The study was conducted on the surgical material from 60 patients of clinical stage 2A (T1N1M0 or T2N0M0) who were treated at the Rostov Research Institute of Oncology from 2012 to 2015. For immunohistochemistry, antibodies to estrogen and progesterone receptors, cytokeratins 5/6, Ki-67, cyclin D1, β-catenin, HER2/neu and EGFR proteins were used. Results. Triple negative breast cancer with the signs of basal epithelium was found to have a significantly higher expression level of Ki-67 compared to non-basal-like one. In some part of triple negative breast cancer samples overexpression of cyclin D1 was observed. The high level of cyclin D1 in the basal-like subtype was less common than in the subtypes without the signs of basal epithelium, but its average value was significantly higher. In triple negative cancer with cyclin D1 overexpression, the loss of β-catenin on the cell membrane and its abnormal accumulation in the cytoplasm was significantly more frequent. β-catenin translocation into the cell nucleus was observed only in basal-like triple negative cancer, and 2 times more often in case of cyclin D1 overexpression. Conclusion. In triple negative breast cancer tumors with overexpression of cyclin D1 and abnormal expression of β-catenin are observed in some cases; these biomarkers can be considered as potential therapeutic targets for this group of tumors

Об основных требованиях к элементам измерительной схемы лазерной корреляционной спектроскопии

Introduction. Laser correlation spectroscopy is a promising method that allows one to analyze sizes of nanoparticles and to evaluate their shape and dynamics of aggregation in liquids. A limited usage of laser correlation spectroscopy is currently caused by insufficient accuracy of existing instruments and data processing algorithms. The paper described the development of laser correlation spectroscopic hardware complex designed for nanoparticles size determination in liquids. The basic requirements for the elements of the device and the approaches used to calculate the signal-to-noise ratio were discussed. The achieved parameters of the laser correlation spectrometer were presented.Aim. To develop the hardware for nanoparticles size determination in liquids and to optimize the parameters of hardware elements to increase signal-to-noise ratio.Materials and methods. Theory of dynamic light scattering to describe scattering of laser radiation in liquids was applied. Fundamental requirements for the elements of the laser correlation spectrometer were described.Results. An original scheme of the laser correlation spectrometer was developed, the basic requirements for the general scheme elements were described. Equations for calculating signal-to-noise ratio were given.Conclusion. The analysis of the main parameters of the elements of the laser correlation spectroscopic scheme were carried out. It helps one to evaluate the expected signal-to-noise ratio in laser correlation spectrometers.Введение. Лазерная корреляционная спектроскопия является перспективным методом, позволяющим анализировать размеры наноструктур, оценивать их форму и динамику агрегации в жидкостях. Ограниченное применение лазерной корреляционной спектроскопии в настоящее время связано с недостаточной точностью и совершенством существующих приборов и алгоритмов обработки данных. В настоящей статье рассмотрены основные требования к элементам, входящим в разрабатываемый лазерный корреляционный спектрометр, предназначенный для определения размеров наночастиц в жидкостях, и оптимизация параметров этих элементов. Обсуждаются подходы, применяемые для расчета отношения сигнал/шум описанной реализации схемы спектрометра. Приведены основные параметры лазерного корреляционного спектрометра, достигнутые при выполнении представленных в статье требований.Цель работы. Разработка аппаратного комплекса для определения размеров наночастиц в жидкости и оптимизация параметров его элементов для увеличения достижимого отношения сигнал/шум.Материалы и методы. В работе с использованием теории динамического рассеяния света построена модель рассеяния лазерного излучения на частицах в жидкости. Описаны основополагающие требования, предъявляемые к элементам схемы лазерного корреляционного спектрометра.Результаты. Разработана оригинальная схема лазерного корреляционного спектрометра, описаны основные требования, предъявляемые к элементам измерительной схемы лазерной корреляционной спектроскопии. Приведены уравнения для расчета шумов основных элементов схемы. Для описанной в работе реализации схемы лазерного корреляционного спектрометра сделаны расчеты достижимого отношения сигнал/шум.Заключение. Проведенный в настоящей статье анализ основных параметров элементов измерительной установки лазерной корреляционной спектроскопии позволяет провести корректный подбор элементов схемы и оценку ожидаемых отношений сигнал/шум

Cholera: Trends in the Development of the Epidemic Process in 2021, Forecast for 2022

The aim of the work was to summarize the results of cholera monitoring in 2021, to assess current trends in the development of the epidemic process, and to predict the epidemiological situation in the Russian Federation for 2022. It was established that within the period of 2012–2021, 4117264 cases of cholera with the spread of infection across 83 countries on all continents were registered in the world and there was a downward trend in the incidence in Asia and Africa. The dynamics of monthly morbidity in 2021 was associated with emergencies as factors of epidemiological risk. Epidemics and outbreaks of cholera were documented against the background of COVID-19 pandemic and laid a double burden on healthcare systems. At the same time, based on the overview of the results of cholera monitoring in the constituent entities of the Russian Federation, it was shown that the forecast of epidemic well-being given for 2021 was fully justified. It has been determined that the increase in the number of non-toxigenic strains of Vibrio cholerae O1 (67) isolated from water bodies compared to 2020 (25) is mainly due to the appurtenance of a number of isolates to clonal complexes. The study of phylogenetic relation has demonstrated that the detection of strains with genotypes which were previously identified in the isolates evidences the persistence potential. The identification of strains with new genotypes, which were earlier established in the strains circulating in other territories, pointed at the possibility of the occasional importations. The forecast of the epidemiological situation on cholera in Russia for 2022 is associated with the continuous existence of risks of introduction. If these epidemiological risks are not realized, a favorable epidemiological situation is predicted regarding this infection in the country. It is expected that the detection of epidemiologically insignificant strains of V. cholerae O1 in environmental water bodies, along with their clones and/or clonal complexes, will remain, including strains that may be an etiological factor in sporadic cases or outbreaks of disease

Значение некоторых иммуноморфологических факторов для определения прогноза аденокарциномы легкого

The aim of this study was to search tumor expression of thymidylate synthetase and some other immunomorphological markers and to determine their prognostic role for pulmonary adenocarcinoma.Methods. Histological and immunohistochemical study of pulmonary adenocarcinoma has been conducted using several markers such as thymidylate synthetase, Ki67, p53, Bcl2, Bax.Results. Thymidylate synthetase and cellular prolif eration activity marker Ki67 were revealed in 100 % of cases; p53, Bcl2 and Bax were revealed in 48 %, 7.9 % and 6.3 %, respectively. The results demonstrated a tendency to decrease 3year eventfree survival by 14 % (p = 0.1007) in patients with high thymidylate synthetase expression in comparison to patients with low expression.Conclusion. Thymidylate synthetase could be used as a prognostic factor of pulmonary adenocarcinoma course.Проведено гистологическое и иммуногистохимическое исследование с применением набора маркеров аденокарциномы легкого (АЛ): тимидилатсинтаза (ТС), Ki67, p53, Bcl2, Bax. Установлено, что ТС и маркер пролиферативной активности Ki67 обнаружены в 100 % наблюдений, p53 – в 48 %, Bcl2 – в 7,9 %, Bax – в 6,3 % общего числа случаев. Показано, что у больных с высоким уровнем экспрессии ТС отмечена тенденция к снижению 3летней бессобытийной выживаемости на 14 % (p = 0,1007) по сравнению с пациентами, у которых отмечена низкая экспрессия. Установлено, что ТС может являться фактором прогноза течения АЛ

ВОЗМОЖНОСТИ ОПРЕДЕЛЕНИЯ ОПУХОЛЕВОЙ СОСУДИСТОЙ ИНВАЗИИ И ЕЕ РОЛЬ В ПРОГНОЗЕ ОПЕРАБЕЛЬНОГО НЕМЕЛКОКЛЕТОЧНОГО РАКА ЛЕГКОГО

Introduction. Vascular invasion in operable lung cancer is an important prognostic factor. Vascular invasion worsens prognosis even in absence of metastases and could require adjuvant chemotherapy. The aims of this study were: 1) to investigate vascular invasion in surgical specimens of non-small cell lung carcinomas (NSCLC) using immunohistochemical detection of CD34+, actin, and cytokeratine expression; 2) to estimate prognostic values of these markers.Methods. Surgical specimens were obtained from 60 patients with NSCLC Т2N0М0 to T3N2M0 stages aged 51 to 73 years (88.3 % were males).Results. Vascular invasion found in primary malignancy significantly worsened outcomes (р = 0.0184) and survival.Conclusion. Vascular invasion is an important predictive factor in patients with malignancies including NSCLC. Immunohistochemistry allowed better detection this process. The most valuable marker is to be CD34+.Опухолевая инвазия сосудов при операбельном раке легкого является важным фактором прогноза. Даже при отсутствии метастатического поражения лимфатических узлов при сосудистой инвазии ухудшается прогноз, что может являться показанием для назначения адъювантной химиотерапии. Для выявления сосудистой инвазии наиболее эффективно проведение иммуногистохимического исследования с антителами СD34

Impact of magnetic nanoparticles on the Casimir pressure in three-layer systems

© 2019 American Physical Society. The Casimir pressure is investigated in three-layer systems where the intervening stratum possesses magnetic properties. This subject is gaining in importance in connection with ferrofluids and their use in various microelectromechanical devices. We present general formalism of the Lifshitz theory adapted to the case of ferrofluid sandwiched between two dielectric plates (walls). The Casimir pressure is computed for the cases of kerosene- and water-based ferrofluids containing a 5% fraction of magnetite nanoparticles with different diameters between silica glass walls. For this purpose, we have found the dielectric permittivities of magnetite and kerosene along the imaginary frequency axis employing the available optical data and used the familiar dielectric properties of silica glass and water, as well as the magnetic properties of magnetite. We have also computed the relative difference in the magnitudes of the Casimir pressure which arises on addition of magnetite nanoparticles to pure carrier liquids. It is shown that for nanoparticles of 20 nm diameter at 2 μm separation between the walls this relative difference exceeds 140% and 25% for kerosene- and water-based ferrofluids, respectively. An interesting effect is found that at a fixed separation between the walls an addition of magnetite nanoparticles with some definite diameter makes no impact on the Casimir pressure. The physical explanation for this effect is provided. Possible applications of the obtained results are discussed