Synthesis of biocompatible composite material based on cryogels of polyvinyl alcohol and calcium phosphates

At the moment, the field of biomedical materials science is actively developing, which aims at creating new functional materials. A developing direction in biomedical materials science is that towards the treatment of diseases associated with bone tissue disorders, using biodegradable composite materials based on polymer and calcium phosphate materials. We developed a material based on polyvinyl alcohol cryogel, mineralized with calcium phosphate. A material based on cryogel of polyvinyl alcohol mineralized with calcium phosphate was developed. The composites were obtained by the method of cyclic freezing–thawing, and the synthesis of calcium phosphates was carried out in situ with heating, stirring, and exposure to microwave radiation. The phase composition, as well as the composition of functional groups, was determined by IR spectroscopy and X-ray phase analysis. Monocytes isolated from human blood showed higher viability compared to the controls

Reactive trityl derivatives: stabilised carbocation mass-tags for life sciences applications

The rational design of novel triarylmethyl (trityl)-based mass tags (MT) for mass-spectrometric (MS) applications is described. We propose a "pKR+ rule" to correlate the stability of trityl carbocations with their MS performance: trityls with higher pKR+ values ionise and desorb better. Trityl blocks were synthesised that have high pKR+ values and are stable in conditions of MS analysis; these MTs can be ionised by matrix as well as irradiation with a 337 nm nitrogen laser. 13C-Labelled tags were prepared for MS quantitation applications. Moreover, the tags were equipped with a variety of functional groups allowing conjugation with different functionalities within (bio)molecules to enhance the MS characteristics of the latter. The MS behaviour of model polycationic trityl compounds with and without the matrix was studied to reveal that poly-trityl clusters are always singly charged under the (MA)LDI-TOF conditions. Several peptide-trityl conjugates were prepared and comparisons revealed a beneficial effect of trityl tags on the conjugate detection in MS. Trityl compounds containing para-methoxy- and dimethylamine groups, as well as a xanthene fragment, showed considerable enhancement in MS detection of model peptides; thus they are promising tools for proteomic applications. Dimethoxytrityl derivatives allow one to distinguish between Arg- and Lys-containing peptides. Maleimido trityl derivatives are suitable for the efficient derivatisation of thiol-containing peptides in pyridine

ОПРЕДЕЛЕНИЕ БРОМИДА ЦЕТИЛТРИМЕТИЛАММОНИЯ ФОТОМЕТРИЧЕСКИМ МЕТОДОМ ЗА СЧЕТ АГРЕГАЦИИ С КАРБОЦИАНИНОВЫМ КРАСИТЕЛЕМ

It was found that the commercial carbocyanine dye IR-783 containing sulfo groups forms aggregates with cetyltrimethylammonium bromide (CTAB) in a slightly alkaline medium yielding a new absorption band, a change in the solution color from blue to yellow (Dl = 350 nm), and a change in the fluorescence intensity in the near-IR region. CTAB was determined by the photometric method  by photographing the reaction mixture in a 96-well plate with a smartphone camera or in a Camag visualizer. The difference between the intensities of the red and blue channels (R – B), corresponding to the yellow color, was used as an analytical signal. The linear range in an aqueous solution is (3 – 25)·10–6 M, the detection limit is 1.6·10–6 M, and the relative standard deviation is 2–5%. The determination is not affected with a number of non-ionic surfactants, inorganic salts and polymers; the anionic surfactants interfere. Other cationic surfactants also give analytical signals, but with different sensitivities. The characteristics of the literature method for the determination of CTAB based on the Coomassie brilliant blue G-250 dye and the proposed method are comparable. A sample of CTAB-containing lysing buffer solution was analyzed.Keywords: cetyltrimethylammonium, cationic surfactants, carbocyanine dye, aggregation, photometry DOI: http://dx.doi.org/10.15826/analitika.2022.26.3.004 Irina A. Stepanova, Anna V. Shik, Evgenii V. Skorobogatov, Anatasiya A.Bartoshevich, Mikhail K. BeklemishevDepartment of Chemistry, Lomonosov Moscow State University,Russian Federation, 119991, GSP-1, Moscow, Leninskie gory, 1, building 3Обнаружено, что коммерческий карбоцианиновый краситель IR-783, содержащий сульфогруппы, в слабощелочной среде образует агрегаты с бромидом цетилтриметиламмония (ЦТАБ) с появлением новой полосы поглощения, изменением цвета раствора с синего на желтый (Dl = 350 нм) и изменением интенсивности флуоресценции в ближней ИК области. ЦТАБ определяли фотометрическим методом, фотографируя реакционную смесь в 96-луночном планшете камерой смартфона или в визуализаторе Camag. В качестве аналитического сигнала использовали разность интенсивностей красного и синего каналов (R – B), соответствующую желтому цвету. Диапазон определяемых концентраций в водном растворе составляет (3 – 25)·10–6 М, предел обнаружения 1.6·10–6 М, относительное стандартное отклонение 2–5 %. Определению не мешает ряд неионных ПАВ, неорганических солей и полимеров, мешают анионные ПАВ. Другие катионные ПАВ также дают сигналы, но с разной чувствительностью. Характеристики литературной методики определения ЦТАБ на основе красителя кумасси бриллиантовый синий G-250 и предлагаемой сопоставимы. Проанализирован образец лизирующего буфера, содержащего ЦТАБ.Ключевые слова: цетилтриметиламмоний, катионные поверхностно-активные вещества, карбоцианиновый краситель, агрегация, фотометрияDOI: http://dx.doi.org/10.15826/analitika.2022.26.3.00

Urokinase-type Plasminogen Activator (uPA) Promotes Angiogenesis by Attenuating Proline-rich Homeodomain Protein (PRH) Transcription Factor Activity and De-repressing Vascular Endothelial Growth Factor (VEGF) Receptor Expression

Urokinase-type plasminogen activator (uPA) regulates angiogenesis and vascular permeability through proteolytic degradation of extracellular matrix and intracellular signaling initiated upon its binding to uPAR/CD87 and other cell surface receptors. Here, we describe an additional mechanism by which uPA regulates angiogenesis. Ex vivo VEGF-induced vascular sprouting from Matrigel-embedded aortic rings isolated from uPA knock-out (uPA(−/−)) mice was impaired compared with vessels emanating from wild-type mice. Endothelial cells isolated from uPA(−/−) mice show less proliferation and migration in response to VEGF than their wild type counterparts or uPA(−/−) endothelial cells in which expression of wild type uPA had been restored. We reported previously that uPA is transported from cell surface receptors to nuclei through a mechanism that requires its kringle domain. Intranuclear uPA modulates gene transcription by binding to a subset of transcription factors. Here we report that wild type single-chain uPA, but not uPA variants incapable of nuclear transport, increases the expression of cell surface VEGF receptor 1 (VEGFR1) and VEGF receptor 2 (VEGFR2) by translocating to the nuclei of ECs. Intranuclear single-chain uPA binds directly to and interferes with the function of the transcription factor hematopoietically expressed homeodomain protein or proline-rich homeodomain protein (HHEX/PRH), which thereby lose their physiologic capacity to repress the activity of vehgr1 and vegfr2 gene promoters. These studies identify uPA-dependent de-repression of vegfr1 and vegfr2 gene transcription through binding to HHEX/PRH as a novel mechanism by which uPA mediates the pro-angiogenic effects of VEGF and identifies a potential new target for control of pathologic angiogenesis

Использование низкобелковых обогащенных крахмаломучных продуктов в диетотерапии больных фенилкетонурией детей в возрасте старше 1 года

Background. The nutrition of children with phenylketonuria includes specialized starch-based products, the range of which is constantly expanding. Our aim was to study the safety of the composition of starchy flakes enriched with a complex of fat-soluble vitamins, natural fruit and berry additives used in the food of children with phenylketonuria. Methods. The study included children under the age of 14 years who were compliant with the previously conducted hypophenylalanine diet, without acute infectious, severe somatic or neurological diseases. The investigated products (starch-rye, wheat, and wheat fruit flakes with a complex of provitamin A and vitamin E) were prescribed instead of previously used low-protein confectionery products in the amount of 20–25 g/day for children under 6 years, 30–40 g — for children aged 6 years and over. The products were given with the recommendation to use alternately, with a duration of at least 10 days, totally for 30 days of the study. The safety of the products was assessed by phenylalanine concentration in the blood (determined by the fluorimetric method). In addition, we assessed the organoleptic qualities of the products and the dynamics of physical development of children. Results. The study included 15 children, mean age 4.4 ± 1.9 years. The initial concentration of phenylalanine in the blood varied from 1.6 to 3.9 mg%, the median — 2.2 mg% (2.0; 2.8). In 30 days after inclusion of starchy flakes in the diet, the content of phenylalanine in the blood did not change and was 2.5 mg% (2.2; 2.7); p = 0.859. The organoleptic properties of the products were rated «excellent» by all patients and their parents (in children under 6 years, only according to the parents’ assessment). The indicators of physical development did not change. There was no adverse events (allergic reactions, dyspepsia, refusal to take food). Conclusion. Introduction of new functional products — low-protein starchy flakes enriched with a vitamin complex and natural fruit and berry additives — in the diet of children with phenylketonuria allows to maintain the level of phenylalanine in the blood at the level of reference values.Обоснование. В питании детей с фенилкетонурией широко используют специализированные продукты на основе крахмалов, ассортимент которых постоянно расширяется.Цель исследования — изучить безопасность состава хлопьев крахмаломучных, обогащенных комплексом жирорастворимых витаминов, натуральными плодовыми и ягодными добавками, используемых в пище детей с фенилкетонурией.Методы. В исследование включали детей в возрасте до 14 лет, комплаентных к ранее проводимой гипофенилаланиновой диете, без острых инфекционных, тяжелых соматических или неврологических заболеваний. Исследуемые продукты — крахмалоржаные, пшеничные и пшеничные плодово-ягодные хлопья с комплексом провитамина А и витамина Е — назначали взамен применявшихся ранее низкобелковых кондитерских изделий в количестве 20–25 г/сут детям младше 6 лет, по 30–40 г — детям, достигших возраста или старше 6 лет. Продукты выдавали с рекомендацией использовать поочередно, продолжительностью не менее 10 сут, всего на 30 сут исследования. Безопасность продуктов оценивали по концентрации фенилаланина в крови (определяли флюориметрическим методом). Дополнительно оценивали органолептические качества продуктов и динамику физического развития детей.Результаты. В исследование включили 15 детей, средний возраст 4,4±1,9 года. Исходная концентрация фенилаланина в крови варьировала от 1,6 до 3,9 мг%, медиана — 2,2 мг% (2,0; 2,8). Через 30 сут после включения в рацион крахмаломучных хлопьев содержание фенилаланина в крови не изменилось и составило 2,5 мг% (2,2; 2,7); р=0,859. Органолептические свойства продуктов были оценены на «отлично» всеми пациентами и их родителями (у детей в возрасте до 6 лет — только согласно оценке родителей). Показатели физического развития не изменились. Нежелательные явления (аллергические реакции, диспепсии, отказ от приема продуктов) не зафиксированы.Заключение. Введение в рацион детей с фенилкетонурией новых функциональных продуктов — хлопьев крахмаломучных низкобелковых, обогащенных витаминным комплексом и натуральными плодовыми и ягодными добавками, позволяет сохранять уровень фенилаланина в крови на уровне референсных значений.ИСТОЧНИК ФИНАНСИРОВАНИЯ Работа выполнена при поддержке гранта Федерального государственного научного учреждения «Всероссийский научно-исследовательский институт крахмалопродуктов» Федерального агентства научных организаций (Московская область). Для целей исследования использовались продукты, безвозмездно предоставленные производителем (опытное производство ФГНУ «ВНИИК» ФАНО).КОНФЛИКТ ИНТЕРЕСОВ Т.Э. Боровик, Н.Н. Семёнова, О.Л. Лукоянова, Н.Г. Звонкова, Т.В. Бушуева, Т.Н. Степанова, В.А. Скворцова — проведение научно-исследовательских работ при поддержке компаний Heinz, Semper, Хипрока Нутришион Ист Лимитед. И.М. Гусева, Е.А. Рославцева, А.К. Геворкян, С.Т. Быкова, Т.Г. Калинина, С.Г. Калиненкова подтвердили отсутствие конфликта интересов.ВЫРАЖЕНИЕ ПРИЗНАТЕЛЬНОСТИ Выражаем благодарность к.м.н. С.Г. Калиненковой (Московский областной научно-исследовательский клинический институт им. М.Ф. Владимирского) за участие в выполнении лабораторной части данного исследования. 

Multidimensional algorithmic thinking development on mental learning platform

The problem of algorithmic thinking development in computer science, computer technology and information technology courses remains relevant despite a lot of research done in the area. The present article is intended to substantiate the mental learning platform for further use of cognitive methods and training tools; it discloses the essence of multidimensional algorithmic thinking and presents mental and embodied (kinaesthetic) programming training tools. The authors arrive at the conclusion that development of multidimensional algorithmic thinking should be carried out through the use of mental algorithmic maps for different styles of thinking, mental and empirical tasks, as well as kinaesthetic simulators. Such training tools involve all channels of perception and greatly contribute to the understanding and better assimilation of “Algorithmization and programming” subject. The results of the research can be useful for computer science teachers at schools and programming teachers at higher educational institutions

Carbocyanine-Based Optical Sensor Array for the Discrimination of Proteins and Rennet Samples Using Hypochlorite Oxidation

Optical sensor arrays are widely used in obtaining fingerprints of samples, allowing for solutions of recognition and identification problems. An approach to extending the functionality of the sensor arrays is using a kinetic factor by conducting indicator reactions that proceed at measurable rates. In this study, we propose a method for the discrimination of proteins based on their oxidation by sodium hypochlorite with the formation of the products, which, in turn, feature oxidation properties. As reducing agents to visualize these products, carbocyanine dyes IR-783 and Cy5.5-COOH are added to the reaction mixture at pH 5.3, and different spectral characteristics are registered every several minutes (absorbance in the visible region and fluorescence under excitation by UV (254 and 365 nm) and red light). The intensities of the photographic images of the 96-well plate are processed by principal component analysis (PCA) and linear discriminant analysis (LDA). Six model proteins (bovine and human serum albumins, γ-globulin, lysozyme, pepsin, and proteinase K) and 10 rennet samples (mixtures of chymosin and pepsin from different manufacturers) are recognized by the proposed method. The method is rapid and simple and uses only commercially available reagents

Carbocyanine-Based Fluorescent and Colorimetric Sensor Array for the Discrimination of Medicinal Compounds

Array-based optical sensing is an efficient technique for the determination and discrimination of small organic molecules. This study is aimed at the development of a simple and rapid strategy for obtaining an optical response from a wide range of low-molecular-weight organic compounds. We have suggested a colorimetric and fluorimetric sensing platform based on the combination of two response mechanisms using carbocyanine dyes: aggregation and oxidation. In the first one, the analyte forms ternary aggregates with an oppositely charged surfactant wherein the dye is solubilized in the hydrophobic domains of the surfactant accompanied with fluorescent enhancement. The second mechanism is based on the effect of the analyte on the catalytic reaction rate of dye oxidation with H2O2 in the presence of a metal ion (Cu2+, Pd2+), which entails fluorescence waning and color change. The reaction mixture in a 96-well plate is photographed in visible light (colorimetry) and the near-IR region under red light excitation (fluorimetry). In this proof-of-concept study, we demonstrated the feasibility of discrimination of nine medicinal compounds using principal component analysis: four cephalosporins (ceftriaxone, cefazolin, ceftazidime, cefotaxime), three phenothiazines (promethazine, promazine, chlorpromazine), and two penicillins (benzylpenicillin, ampicillin) in an aqueous solution and in the presence of turkey meat extract. The suggested platform allows simple and rapid recognition of analytes of various nature without using spectral equipment, except for a photo camera

Potassium and magnesium deficiency, its role in cardiovascular disease development and possibilities of correction

Aim. To evaluate the significance of potassium and magnesium in human health formation and their role in development of functional disorders of cardiovascular and nervous system and in development and progression of cardiovascular diseases. Materials and methods. Data from 55 literature sources published in Russia and abroad in the period of 1972–2018 years are reviewed. Results. Potassium has an important role in cells bioelectrical activity organization, cell action potentials formation and neuromuscular excitability and conductibility sustentation. Hypokalemia symptoms can be quite various. Frequent ones include neuromuscular conductibility disorders, various changes in cardiovascular system (myocardial contractile function decrease, blood pressure (BP) decrease, cardiac cavities dilatation). Potassium intake increase is followed by lower incidence of cardiovascular and cerebrovascular events, new cases of diabetes mellitus (DM) type 2, left ventricular hypertrophy, cardiac insufficiency, and arrhythmias. Magnesium is a universal regulator of biochemical and physiological processes in the body, a cofactor of more than 300 enzymes participating in biochemical reactions, and a natural physiologic potassium antagonist. It reduces potassium release from sarcoplasmic reticulum and protects cells from potassium overload in conditions of ischemia. Therefore magnesium reduces systemic and pulmonary vascular resistance that results in systemic BP reduction and moderate cardiac index increase. Also reliable evidence indicating moderate but clinically significant antihypertensive effect of magnesium medications was received. Magnesium deficiency is associated with increase of total cholesterol level, low-density lipoprotein, and triglycerides. Serum magnesium level is inversely proportional to the degree of cardiovascular disorders development risk, particularly of cardiac rhythm disorders and IHD complications. European Food Safety Authority (EFSA) confirmed that patients’ health status improved after a period of magnesium adequate intake. Even severe hypokalemia and hypomagnesemia often remain non-diagnosed in clinical practice. Medical practitioner of any kind should remember of potassium and magnesium deficiency clinical manifestations in order to manage it or prevent its development in patients with risk factors by adequate treatment assignment. Described potassium and magnesium interrelations as well as relatively high frequency and severity of combined deficit of these macronutrients justify advisability of the use of combined medications containing К+ and Mg2+in treatment of many disorders. An additional effect is observed when these electrolytes levels are corrected together. Conclusion. Control of electrolyte balance, first of all, of potassium and magnesium balance, should be an intrinsic part of present day clinical practice. In patients with high risk of hypokalemia and hypomagnesemia development either its correction in case of detection or prevention of potassium and magnesium deficiency development should be performed. Potassium and magnesium balance maintenance provides additional therapeutic effect in patients with AH, DM, congestive heart failure, IHD (including myocardial infarction), as well as in patients with high risk of stroke or severe ventricular arrhythmia development

Refugee Flows at Border Crossing Points: Legal, Social and Language Aspects

Migration as a social phenomenon has always been a part of the world, but it has never reached such scope as in the recent years. Violent conflicts, instability, poverty and natural disasters force people to move in search of protection and better life. In 2017, about one million first instance decisions were issued in EU, most of which were asylum protection for Syrians, Afghans and Iraqis fleeing the war zones and hostilities. In Eastern Europe, the hotbed of tension is associated with Ukraine where the government is using military forces against split-away Donbass. Flows of refugees rushed to EU countries and Russia, which brought about numerous challenges and demanded huge political, organizational, humanitarian, financial and other strengths. The purpose of this research is to investigate limited aspects of refugee crises in Western and Eastern Europe on the example of France, the UK and Russia. Different reasons, character and forms of these mass movements of people are directly related to international legal protection rules. However, common legal basis has found national specific realization in terms of legal and language challenges in addressing the refugee crisis at crossing points and temporary settlement zones. Qualitative analysis of the research combines theoretical and empirical activities of three European countries in refugee settings and is supported by comparative and contrasting methods of analysis. Experiences studied in the article contribute to international practice of dealing with refugee flows in legal and language context