183 research outputs found
Rational development of protein formulations in solid and solution states
Development of protein formulations in the solid and solution state involves stability studies during long-term storage (2-3 years). A long-term study of a protein under conditions leading to its rapid physical and chemical degradation often results in excessive use of resources and severe time constraints. To minimize these problems, a thorough preformulation study of protein behavior under different conditions is necessary. An in depth understanding of the properties of proteins in both the solution and solid state may subsequently result in selection of conditions leading to adequate stability during storage.
Preformulation studies of a protein in solution often involve a three step approach. In this method a protein is first characterized under a range of conditions (e.g. pH, temperature, etc.), and the data is then summarized in the form of an empirical phase diagram. This information is then used to design a high throughput screening approach to identify stabilizing compounds. This approach was employed for preformulation studies of vaccines against Clostridium difficile ( C. difficile)-associated disease. Such vaccines contain formaldehyde treated toxoids A and B in free or adjuvant bound form. Studies of C. difficile toxins and toxoids under a range of conditions revealed a stabilizing effect of formaldehyde crosslinking on the thermal stability of the toxoids. Furthermore, screening for stabilizing compounds resulted in the identification of conditions and specific compounds that lead to enhanced thermal stability of free and bound to adjuvant toxoids.
Preformulation studies of proteins in the solid state usually involve characterization of an amorphous solid in general (e.g. moisture content, crystallinity, structural relaxation, etc.) and specific protein properties (e.g. extent of protein structure preservation). Unfortunately, these characteristics of the solid and protein cannot usually predict protein stability during storage. Therefore, a more in depth understanding of amorphous matrices is needed. To understand the role of interactions between protein and expient as well as the homogeneity of protein/excipient mixtures, a study of a model system containing human Growth Hormone (hGH) and sugars (sucrose and trehalose) was performed.
This study revealed that the extent of protein/excipient interaction can be used to describe the degree of homogeneity of a lyophilized mixture which can be related to the cryo- and lyo-protecting properties of the excipients. Additionally, it was seen that the rate of structural relaxation is proportional to the rate of insoluble aggregate formation. These studies of proteins in solution and the solid state allowed for the identification of conditions for long term stability studies of C. difficile vaccines and contributed to our understanding of the role of interactions between protein and excipient in lyophilized solids
РИСК РАЗВИТИЯ ПНЕВМОНИИ И ПОЛИМОРФИЗМ ГЕНОВ TLR2 И TLR4: МЕТА-АНАЛИЗ
Pneumonia is one of the most common infections with high mortality rates. The gene polymorphism of Toll-like receptors that belong to the first line of defense of the immune system can make a considerable contribution to individual variability due to the risk of pneumonia. Today this issue has not been adequately explored and the data available in the literature are conflicting.Objective: to carry out a meta-analysis of the association between Toll-like receptor gene polymorphic variants and the risk of pneumonias and its coinfections.Methods. A meta-analysis was carried out to detect a possible association of the risk of pneumonia and coinfections with single nucleotide polymorphisms (SNP) in the TLR2 (rs5743708 (2258 G>A; Arg753Gln) and TLR4 (rs4986790 (896A>G; Asp299Gly) genes. The investigation enrolled 2312 (682 patients/1630 control individuals) and 3075 (910/2165) Caucasians for each SNP, respectively. As the rate of minor alleles of both polymorphic variants was less than 5%; the analysis was made only for a dominant genetic model.Results. Analysis of the study group showed that the A allele of TLR2 rs5743708 was associated with the risk of pneumonia (OR = 1.90; 95% CI: 1.02—3.54; P=0.042) while TLR4 rs4986790 was not associated with pneumonia. Analysis of subgroups (children/adults and community-acquired/nosocomial pneumonia) revealed no significant effects.Conclusion. The A allele of TLR2 rs5743708 may be a risk factor for susceptibility to pneumonia. These results have promises for their clinical application; however, due to the high heterogeneity and insufficient sizes of samples, these results need to be confirmed by further investigations.Пневмония является одной из наиболее распространенных инфекций с высоким уровнем смертности. Полиморфизм генов толл-подобных рецепторов, относящихся к первой линии защиты иммунной системы, может вносить существенный вклад в индивидуальную вариабельность в связи с риском развития пневмонии. На сегодняшний день этот вопрос недостаточно изучен, а имеющиеся литературные данные противоречивы. Цель исследования. Мета-анализ ассоциации полиморфных вариантов генов толл-подобных рецепторов и риска развития пневмонии и сопутствующих ей инфекций. Методы. Для обнаружения возможной ассоциации риска развития пневмонии и сопутствующих инфекций с однонуклеотидными полиморфизмами (SNP) в генах TLR2 rs5743708 (2258 G>A; Arg753Gln) и TLR4 rs4986790 (896A>G; Asp299Gly) был выполнен мета-анализ. В исследование было включено 2312 (682 пациента / 1630 индивидуумов контрольной группы) и 3075 (910/2165) представителей европеоидной расы для каждого SNP соответственно. Так как частота минорных аллелей обоих полиморфных вариантов составляет менее 5%, анализ выполнен только для доминантной генетической модели. Результаты. При анализе общей группы аллель А гена TLR2 (rs5743708) показал ассоциацию с риском развития пневмонии (OR=1,90, 95% ДИ: 1,02—3,54, p=0,042), в то время как для гена TLR4 (rs4986790) ассоциации с пневмонией выявлено не было. При анализе подгрупп (дети/взрослые и внебольничная пневмония/нозокомиальная пневмония) значимые эффекты отсутствовали. Выводы. Аллель А гена TLR2 (rs5743708) может быть фактором риска восприимчивости к пневмонии. Данные результаты имеют перспективы для их использования в клинической практике, однако, в связи с высокой гетерогенностью и недостаточными размерами выборок, требуется подтверждение этих результатов в дальнейших исследованиях
A MODERN VIEW ON THE PROBLEM OF TREATMENT OF UROTHELIAL CANCER
Urothelial cancer (UC) is one of the leading onco-urological diseases. The lack of clinical manifestations of the disease at earlier stages does not allow assigning an adequate therapy in good time. Currently they extensively use conventional methods of treatment, which are constantly improving. Nevertheless, such methods are not always sufficiently effective: they neither always avert recurring, nor ensure sufficient remission and longevity of a patient. Identification of new trends in the early diagnostics of not only cancers but also pre-cancers plays an important role in forming conceptually new approaches to medical treatments. Molecular genetic features of UC have shown a significant chromosomal mutational variability, the dependence of genetic variations on the tumor invasion level, as well as its high level of immunizing power. Successes achieved in understanding the processes taking place not only in the tumor microenvironment but also in tumors have enabled creating fundamentally new anticancer drugs and achieving a significant progress in treating UC. This article presents a new classification of UCs based on immune histochemical data and molecular genetic characteristics of tumors, presents a cluster analysis of various types of UCs, recites present-day data on the disease incidence, analyses up-to-date conventional and innovative methods of UC treatment including non-specific and specific immunotherapy, describes the underlying mechanisms preventing tumors to evade immune surveillance, shows the role of immune checkpoints and their inhibitors, target and cytokine therapies, tumor vaccines, cell-based therapies, combined and integral methods of noninvasive and metastatic UC, as well as describes the results of clinical trials when using various methods of tumor treatments
Mesozoic intraplate granitic magmatism in the Altai accretionary orogen, NW China: implications for the orogenic architecture and crustal growth
The Central Asian Orogenic Belt (CAOB) is the world's largest Phanerozoic accretionary orogen and is the most important site for juvenile crustal growth in the Phanerozoic. In this work, we employed U-Pb zircon geochronology to identify the early and middle Mesozoic intraplate granitic intrusive events in the Chinese Altai segment of the southern CAOB in order to better understand the crustal architecture of the CAOB. We also used whole-rock geochemical, Sr-Nd isotopic and zircon Hf isotopic data to constrain the generation for these granitic rocks and to evaluate the implications for vertical crustal growth in this region. The Early Mesozoic granitic intrusions were emplaced between 220 and 200 Ma in the central Altai “microcontinental terrane” (also widely referred to as Units 2 and 3). The granites have shoshonitic and high-K calc-alkaline affinities and show the characteristics of differentiated I-type granite. The whole-rock initial 87Sr/86Sr ratios (0.7058-0.7128) and εNd(210) values (−0.6 to −4.3), as well as the zircon εHf(t) values (−4.0 to +5.0) and two-stage Hf model ages (0.94-1.52 Ga), suggest that the granitic magmas were produced from a mixed source with both mantle-derived and recycled crustal components. The middle Mesozoic granites were emplaced at ~150 Ma in the southern Altai “accretionary terrane” (Units 4 and 5). They show A-type characteristics with the REE tetrad effect and have positive εNd(151) whole-rock values of +1.0 to +5.2 and two-stage Nd model ages (TDM2) of 0.6 to 1.0 Ga. Zircon Hf data show positive zircon εHf(151) values of +1 to +8 and two-stage Hf model ages of 0.6 to 1.2 Ga. The Nd-Hf isotopic data suggest that the granitic magmas were derived from short-lived juvenile mantle-derived materials. Thus, the isotopic signatures of all the Mesozoic granites from the central (old terrane) and southern (young accretional terrane) Altai suggest that the basement of both terranes has retained its original nature. The data further imply that the Altai orogen has kept its original architecture of Paleozoic horizontal accretion during Mesozoic time, as commonly observed in accretionary orogens where horizontal tectonics are dominant. All the early Mesozoic intrusions in the Altai were emplaced in an intraplate anorogenic setting; hence are distinguished from the contemporaneous syn- or post-orogenic magmatism in the eastern CAOB. We conclude that the early Mesozoic granites in the CAOB were emplaced in a variety of tectonic settings
EARLY NEOPROTEROZOIC CRUST FORMATON IN THE DZABKHAN MICROCONTINENT, CENTRAL ASIAN OROGENIC BELT
The Dzabkhan microcontinent was defined by [Mossakovsky et al., 1994] as a cratonic terrane with an early Precambrian basement that combines highgrade metamorphic complexes of the Songino, Dzabkhan, Otgon, Baidarik, Ider and Jargalant Blocks. However, early Precambrian ages have so far only been recognized in the Baidarik and Ider blocks [Kozakov et al., 2007, 2011; Kröner et al., 2015].The Dzabkhan microcontinent was defined by [Mossakovsky et al., 1994] as a cratonic terrane with an early Precambrian basement that combines highgrade metamorphic complexes of the Songino, Dzabkhan, Otgon, Baidarik, Ider and Jargalant Blocks. However, early Precambrian ages have so far only been recognized in the Baidarik and Ider blocks [Kozakov et al., 2007, 2011; Kröner et al., 2015]
«AIRES» SHARED RESEARCH FACILITIES (IPGG RAS, St. PETERSBURG): SCIENTIFIC EQUIPMENT, MAIN RESEARCH DIRECTIONS AND RESULTS
The "AIRES" Shared Research Facilities (SRF) is a high-tech laboratory complex based on the Institute of Precambrian Geology and Geochronology RAS (IPGG RAS, St. Petersburg). The Institute conducts geological, mineralogical, geochronological, isotope-geochemical and paleontological studies aimed at solving the problems of the formation and evolution of the Earth's continental crust in the Precambrian and Phanerozoic. The methodological developments of the "AIRES" SRF make it possible to interpret the conditions of occurrence of igneous, metamorphic and sedimentary rocks and minerals, as well as their age. The ongoing research includes studies on geology, geodynamics, stratigraphy, petrology, lithology, isotope geochemistry, geochronology, as well as paleogeography, archeology, soil science, ecology, and chemistry
Evaluation of a method for the determination of antibacterial activity of chitosan
© 2016, Pleiades Publishing, Inc.A method for the determination of the antimicrobial activity of chitosan with the use of organic salts for the production of pH in the range of 5.5–8.2 was studied. The double-dilution method demonstrated the effectiveness of the determination of the antimicrobial activity of chitosan samples with different molecular weights and solubilities. It was found that the antibacterial activity increased at low pH values with increasing molecular weight, but chitosans with a molecular weight of 5–6 kDa showed higher activity at neutral and slightly alkaline pH levels. Determination of the antimicrobial activity of various chitosan samples at different pH values allowed a more reliable assessment of the potential biological activity of chitosan
ЦЕНТР КОЛЛЕКТИВНОГО ПОЛЬЗОВАНИЯ «АИРИЗ» (ИГГД РАН, г. САНКТ-ПЕТЕРБУРГ): НАУЧНОЕ ОБОРУДОВАНИЕ, ОСНОВНЫЕ НАПРАВЛЕНИЯ ИССЛЕДОВАНИЙ И РЕЗУЛЬТАТЫ
The "AIRES" Shared Research Facilities (SRF) is a high-tech laboratory complex based on the Institute of Precambrian Geology and Geochronology RAS (IPGG RAS, St. Petersburg). The Institute conducts geological, mineralogical, geochronological, isotope-geochemical and paleontological studies aimed at solving the problems of the formation and evolution of the Earth's continental crust in the Precambrian and Phanerozoic. The methodological developments of the "AIRES" SRF make it possible to interpret the conditions of occurrence of igneous, metamorphic and sedimentary rocks and minerals, as well as their age. The ongoing research includes studies on geology, geodynamics, stratigraphy, petrology, lithology, isotope geochemistry, geochronology, as well as paleogeography, archeology, soil science, ecology, and chemistry.Центр коллективного пользования (ЦКП) «АИРИЗ» – высокотехнологичный лабораторный комплекс на базе Института геологии и геохронологии докембрия РАН (ИГГД РАН, г. Санкт-Петербург), проводящий геологические, минералогические, геохронологические, изотопно-геохимические и палеонтологические исследования, направленные на решение проблем формирования и эволюции континентальной коры Земли в докембрии и фанерозое. Методические разработки ЦКП «АИРИЗ» позволяют расшифровать условия происхождения магматических, метаморфических и осадочных пород и минералов, а также определить их возраст. Выполняемые работы охватывают различные области геологии, геодинамики, стратиграфии, петрологии, литологии, изотопной геохимии, геохронологии, а также палеогеографии, археологии, почвоведения, экологии и химии
THE SYNTHESIS, STUDY OF PHYSICOCHEMICAL PROPERTIES, AND EVALUATION OF CATALYTIC ACTIVITY OF A THREE-WAY CATALYST MODIFIER CONTAINING EUROPIUM (III) OXIDE
Modification of the applied Pt-containing catalysts with rare-earth metals is one of effective ways to increase their activity and resistance to thermal deactivation, which is associated with both an increase in thermal stability of the texture and structure of the carrier material and an increase in the degree of dispersion and resistance to sintering of the applied platinum metals (PM) when exposed to high tempera-tures. Conflicting data make it difficult to select a suitable modifier for the use as part of a three-way catalyst in the exhaust treatment system of gasoline-powered cars, whose function is to simultaneously convert CO, CxHy and NOx. In this work, the effect of europium-modified Pt-containing γ-Al2O3-based catalyst on its physicochemical properties and activity in the oxidation of CO, CxHy, and NOx reduction processes was evaluated. The catalytic activity was evaluated by passing a gas mixture simulating the exhaust of a gasoline-powered car through the catalyst applied onto the surface of a cylindrical honey-comb block with simultaneous measurement of the degree of conversion of toxic components into rela-tively non-toxic CO2, N2 and H2O in the temperature range from 100°C to 400°C. The modification of the Pt/γ-Al2O3 catalytic system with europium was shown to enhance the activity in all three reactions studied, indicating a great potential for the use as a modifier of a three-way catalyst. © 2023, Azerbaijan National Academy of Sciences. All rights reserved
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