38 research outputs found
Possibility of using mathematical analysis methods to evaluate the potency of antibodies to hepatitis B virus surface antigen in human immunoglobulin preparations
Get PDFScientific relevance. Anti-hepatitis B virus surface-antigen (HBsAg) immunoglobulins are used to prevent hepatitis B in adults and children after exposure and to treat mild to moderate acute viral hepatitis B. The clinical effectiveness of human immunoglobulin preparations is determined by their potency, which is assessed by the content of antibodies to hepatitis B virus surface antigen (anti-HBs antibodies). Currently, this assessment involves using immunoassay techniques, such as enzyme-linked immunosorbent assay (ELISA).Aim. This study examined several mathematical methods for analysing the experimental data obtained in ELISA-based anti-HBs antibody potency assays of human immunoglobulin preparations.Materials and methods. This study used the international standard for human anti-HBs immunoglobulin, two immunoglobulin preparations, and an ELISA test kit for the detection and quantification of anti-HBs antibodies in serum or plasma samples.Results. Using sandwich ELISA, the authors ascertained that the measured anti-HBs antibody concentration depended on the choice of calibration curve calculation method (i.e. manual analysis, parallel-line analysis using PARALINE software, linear regression, and 4-parameter logistic regression). The measured anti-HBs antibody concentrations varied by ± 19 IU/mL. According to the study results, an incorrectly selected method of data analysis can lead to an erroneous calculation of the analyte potency (concentration) in the test sample.Conclusions. The study demonstrated the need for improved mathematical methods for the evaluation of experimental data used to determine the anti-HBs antibody concentration in human immunoglobulin preparations. It is essential to switch from manual to automated calculation (for example, using a 4-parameter logistic model), taking into account the requirements for bioanalytical methods and the capabilities of the available equipment
History of Hydrocarbon Accumulation in the Giant Carbonate Reservoirs - Case Studies of the Precaspian Basin
No full textSoluble gC1qR is an autocrine signal that induces B1R expression on endothelial cells
Get PDFBradykinin (BK) is one of the most potent vasodilator agonists known and belongs to the kinin family of proinflammatory peptides. BK induces its activity via two G protein-coupled receptors: BK receptor 1 (B1R) and BK receptor 2. Although BK receptor 2 is constitutively expressed on endothelial cells (ECs), B1R is induced by IL-1β. The C1q receptor, receptor for the globular heads of C1q (gC1qR), which plays a role in BK generation, is expressed on activated ECs and is also secreted as soluble gC1qR (sgC1qR). Because sgC1qR can bind to ECs, we hypothesized that it may also serve as an autocrine/paracrine signal for the induction of B1R expression. In this study, we show that gC1qR binds to ECs via a highly conserved domain consisting of residues 174-180, as assessed by solid-phase binding assay and deconvolution fluorescence microscopy. Incubation of ECs (24 h, 37°C) with sgC1qR resulted in enhancement of B1R expression, whereas incubation with gC1qR lacking aa 174-180 and 154-162 had a diminished effect. Binding of sgC1qR to ECs was through surface-bound fibrinogen and was inhibited by anti-fibrinogen. In summary, our data suggest that, at sites of inflammation, sgC1qR can enhance vascular permeability by upregulation of B1R expression through de novo synthesis, as well as rapid translocation of preformed B1R
Review on the development of truly portable and in-situ capillary electrophoresis systems
No full textCapillary electrophoresis (CE) is a technique which uses an electric field to separate a mixed sample into its constituents. Portable CE systems enable this powerful analysis technique to be used in the field. Many of the challenges for portable systems are similar to those of autonomous in-situ analysis and therefore portable systems may be considered a stepping stone towards autonomous in-situ analysis. CE is widely used for biological and chemical analysis and example applications include: water quality analysis; drug development and quality control; proteomics and DNA analysis; counter-terrorism (explosive material identification) and corrosion monitoring. The technique is often limited to laboratory use, since it requires large electric fields, sensitive detection systems and fluidic control systems. All of these place restrictions in terms of: size, weight, cost, choice of operating solutions, choice of fabrication materials, electrical power and lifetime. In this review we bring together and critique the work by researchers addressing these issues. We emphasize the importance of a holistic approach for portable and in-situ CE systems and discuss all the aspects of the design. We identify gaps in the literature which require attention for the realization of both truly portable and in-situ CE systems
Изучение возможности применения математических методов анализа для оценки специфической активности антител к поверхностному антигену вируса гепатита В в препаратах иммуноглобулинов человека
Get PDFScientific relevance. Anti-hepatitis B virus surface-antigen (HBsAg) immunoglobulins are used to prevent hepatitis B in adults and children after exposure and to treat mild to moderate acute viral hepatitis B. The clinical effectiveness of human immunoglobulin preparations is determined by their potency, which is assessed by the content of antibodies to hepatitis B virus surface antigen (anti-HBs antibodies). Currently, this assessment involves using immunoassay techniques, such as enzyme-linked immunosorbent assay (ELISA).Aim. This study examined several mathematical methods for analysing the experimental data obtained in ELISA-based anti-HBs antibody potency assays of human immunoglobulin preparations.Materials and methods. This study used the international standard for human anti-HBs immunoglobulin, two immunoglobulin preparations, and an ELISA test kit for the detection and quantification of anti-HBs antibodies in serum or plasma samples.Results. Using sandwich ELISA, the authors ascertained that the measured anti-HBs antibody concentration depended on the choice of calibration curve calculation method (i.e. manual analysis, parallel-line analysis using PARALINE software, linear regression, and 4-parameter logistic regression). The measured anti-HBs antibody concentrations varied by ± 19 IU/mL. According to the study results, an incorrectly selected method of data analysis can lead to an erroneous calculation of the analyte potency (concentration) in the test sample.Conclusions. The study demonstrated the need for improved mathematical methods for the evaluation of experimental data used to determine the anti-HBs antibody concentration in human immunoglobulin preparations. It is essential to switch from manual to automated calculation (for example, using a 4-parameter logistic model), taking into account the requirements for bioanalytical methods and the capabilities of the available equipment.Актуальность. Препараты иммуноглобулинов человека, содержащие в составе антитела к поверхностному антигену вируса гепатита В (HBsAg), являются средством экстренной профилактики гепатита В у взрослых и детей и применяются для лечения легких и среднетяжелых форм острого вирусного гепатита В. Клиническая эффективность таких препаратов определяется специфической активностью, оцениваемой по содержанию антител к поверхностному антигену вируса гепатита В (anti-HBs антитела), которую в настоящее время определяют с использованием метода иммуноферментного анализа (ИФА).Цель. Анализ различных математических методов оценки экспериментальных данных, полученных с применением ИФА для определения активности антител к поверхностному антигену вируса гепатита В в препаратах иммуноглобулинов человека.Материалы и методы. В работе использовали международный стандартный образец иммуноглобулина человека, содержащий anti-HBs антитела; препараты иммуноглобулинов; набор реагентов для иммуноферментного качественного и количественного определения антител к HBsAg в сыворотке (плазме) крови.Результаты. С использованием сэндвич-варианта ИФА установлена зависимость получаемого результата определения концентрации anti-HBs антител от выбора способа построения калибровочного графика («ручной» подход, метод параллельных линий с использованием программы «PARALINE», метод линейной регрессии, 4-параметрическая логистическая модель). Разброс полученных значений концентрации anti-HBs антител составил ±19 МЕ/мл от среднего значения. Установлено, что неверно подобранный метод обработки данных может приводить к ошибочным расчетам значений активности (концентрации) анализируемого вещества в испытуемом образце.Выводы. Показана необходимость совершенствования математических методов оценки экспериментальных данных, используемых для определения концентрации anti-HBs антител в препаратах иммуноглобулинов человека, и важность перехода от «ручного» к автоматизированному обсчету получаемых результатов (например, с использованием 4-параметрической логистической модели) в соответствии с требованиями, предъявляемыми к биоаналитическим методам испытаний, и с учетом возможностей современного оборудования
ЭПИТАКСИАЛЬНЫЕ ПЛЕНКИ СЕЛЕНИДА ЦИНКА НА ПОРИСТОМ КРЕМНИИ
Get PDFZnSe epitaxial films are grown on (111)- and (100)-oriented Si substrates with a porous buffer layer by the thermal evaporation of ZnSe compound. The crystal structure of the deposited films was controlled by X-ray diffraction. The morphology of the films was studied by high-resolution scanning electron microscopy. It was demonstrated the porous buffer layer provides improving the quality of the films compared with films deposited on the monolithic silicon.Эпитаксиальные пленки ZnSe выращены путем термического испарения соединения ZnSe на подложках Si ориентации (111) и (100) с буферным пористым слоем. Кристаллическая структура осаждаемых пленок контролировалась методом рентгеновской дифрактометрии. Морфология пленок изучалась методом растровой электронной микроскопии высокого разрешения. Установлено, что использование пористого буферного слоя позволяет повысить качество пленок по сравнению с пленками, осажденными на монолитный кремний
Nanostructural organization of naturally occurring composites - part II: silica-chitin-based biocomposites
No full textInvestigations of the micro- and nanostructures and chemical composition of the sponge skeletons as examples for natural structural biocomposites are of fundamental scientific relevance. Recently, we show that some demosponges (Verongula gigantea, Aplysina sp.) and glass sponges (Farrea occa, Euplectella aspergillum) possess chitin as a component of their skeletons. The main practical approach we used for chitin isolation was based on alkali treatment of corresponding external layers of spicules sponge material with the aim of obtaining alkali-resistant compounds for detailed analysis. Here, we present a detailed study of the structural and physicochemical properties of spicules of the glass sponge Rossella fibulata. The structural similarity of chitin derived from this sponge to invertebrate alpha chitin has been confirmed by us unambiguously using physicochemical and biochemical methods. This is the first report of a silica-chitin composite biomaterial found in Rossella species. Finally, the present work includes a discussion related to strategies for the practical application of silica-chitin-based composites as biomaterials
Retrospective Analysis of Viral Hepatitis B Incidence in Russia from 2013 to 2017 in the Context of Preventive Vaccination
Get PDFThe article presents the results of a retrospective analysis of viral hepatitis B incidence in the Russian Federation from 2013 to 2017, taking into account the use of vaccines included into the National Immunisation Schedule and the Immunisation Programme in Case of Epidemic Outbreaks. The analysis of the data revealed a trend towards a reduction in the incidence of acute and chronic forms of hepatitis B in the territory of the Russian Federation during the past five years. The reduction of viral hepatitis B incidence was achieved thanks to a higher vaccination coverage of both children and adults. The article presents an overview of monovalent and combination recombinant hepatitis B vaccines licensed in the Russian Federation. It describes the WHO position on preventive vaccination against viral hepatitis B, and pays special attention to vaccination of people at risk. The article considers promising areas for improving immunobiological products for hepatitis B prevention, including new technologies used in vaccine production, development and introduction of new adjuvants or adjuvants systems, and development of therapeutic vaccines
EPITAXIAL FILMS OF ZINC SELENIDE ON POROUS SILICON
No full textZnSe epitaxial films are grown on (111)- and (100)-oriented Si substrates with a porous buffer layer by the thermal evaporation of ZnSe compound. The crystal structure of the deposited films was controlled by X-ray diffraction. The morphology of the films was studied by high-resolution scanning electron microscopy. It was demonstrated the porous buffer layer provides improving the quality of the films compared with films deposited on the monolithic silicon
