26 research outputs found
Improvement of the quality of higher school training of future vocational teachers on the basis of application of IT-technologies
The article deals with the possible use of IT-technologies for improvement of quality of future vocational teachers training in the formation of a new educational system.The experience of the development of the electronic textbook for the discipline «Devices and automats for precision and quality control» is presentedАнализируются возможности использования IT-технологий для повышения качества подготовки будущих педагогов профессионального обучения. Представлен опыт разработки электронного учебного пособия по дисциплине «Приборы и автоматы для контроля точности и качества
Fostering Patriotism in Educational Institutions of Sredneuralsk City as a Way to Prevent Extremism During a Special Military Operation
Данная статья рассматривает основные направления работы по воспитанию патриотизма среди молодежи в образовательной среде города Среднеуральска как способ профилактики экстремистских настроений. Дается краткая характеристика основных методов и механизмов работы по воспитанию патриотизма в образовательных учреждениях Среднеуральска и реализация потенциала ветеранов СВО в данных мероприятиях.This article examines the main directions of work on the education of patriotism among young people in the educational environment of Sredneuralsk, as a way to prevent extremist sentiments. A brief description of the main methods and mechanisms of work on the education of patriotism in educational institutions of Sredneuralsk, and the realization of the potential of veterans of a Special military operation in these events is given
NK cells expansion <i>in vitro</i> is followed by loss of inhibitory KIR expression
NK cells are innate lymphocytes that are able to eliminate altered cells, which makes them promising for the immunotherapy of viral diseases and tumors. The NK cell population is characterized by high phenotypic and functional diversity. In particular, in the pool of highly differentiated NK cells in the presence of cytomegalovirus (HCMV), a population of adaptive cells can be formed, characterized by a high lifespan and high cytotoxicity. However, in order to carry out a cytotoxic reaction, a NK cell must undergo a licensing process, during which it acquires the expression of NKG2A and KIRs. Currently, there are many effective methods of NK cell accumulation for subsequent use in therapy, one of them is the stimulation with IL-2 and K562-mbIL21 feeder cells. Highly differentiated adaptive-like NK cells are able to expand in respond to such stimulation. However, the phenotype of actively expanding NK cells dynamically changes. Loss of inhibitory KIR expression during intense proliferation of NK cells may adversely affect their cytotoxic potential. This work shows that highly differentiated CD56dimNKG2C+ NK cells from HCMV-seropositive individuals have a high proportion of KIR2DL2/3+ cells. This may indicate a high stability of KIR receptor expression in this population. We have shown that CD56dimNKG2C+ clonal cultures obtained by stimulation with IL-2 and K562- mbIL21 are characterized by high stability of KIR2DL2/3 expression compared to NKG2C-negative and less differentiated CD56brightNKG2C+. Also, in heterogeneous cultures of adaptive NK cells precursors CD57- CD56dimNKG2C+, a higher expression level of KIR2DL2/3 was observed in comparison with NKG2C-negative cultures of CD57-CD56dimNKG2C-. Thus, the accumulation of NK cells upon stimulation with IL-2 and K562- mbIL2 feeder cells can lead to loss of expression of KIR receptors and a decrease in their functional activity. However, cultures of highly differentiated NK cells of HCMV-seropositive individuals CD56dimNKG2C+, as well as cultures of precursors of adaptive NK cells CD57-CD56dimNKG2C+, are characterized by a greater stability of KIR2DL2/3 expression. As a result, stimulation with IL-2 and K562-mbIL21 feeder cells can be used to accumulate adaptive-like cells and their progenitors with stable inhibitory KIR expression and high cytotoxic potential
Fucans, but Not Fucomannoglucuronans, Determine the Biological Activities of Sulfated Polysaccharides from Laminaria saccharina Brown Seaweed
Sulfated polysaccharides from Laminaria saccharina (new name: Saccharina latissima) brown seaweed show promising activity for the treatment of inflammation, thrombosis, and cancer; yet the molecular mechanisms underlying these properties remain poorly understood. The aim of this work was to characterize, using in vitro and in vivo strategies, the anti-inflammatory, anti-coagulant, anti-angiogenic, and anti-tumor activities of two main sulfated polysaccharide fractions obtained from L. saccharina: a) L.s.-1.0 fraction mainly consisting of O-sulfated mannoglucuronofucans and b) L.s.-1.25 fraction mainly composed of sulfated fucans. Both fractions inhibited leukocyte recruitment in a model of inflammation in rats, although L.s.-1.25 appeared to be more active than L.s.-1.0. Also, these fractions inhibited neutrophil adhesion to platelets under flow. Only fraction L.s.-1.25, but not L.s.-1.0, displayed anticoagulant activity as measured by the activated partial thromboplastin time. Investigation of these fractions in angiogenesis settings revealed that only L.s.-1.25 strongly inhibited fetal bovine serum (FBS) induced in vitro tubulogenesis. This effect correlated with a reduction in plasminogen activator inhibitor-1 (PAI-1) levels in L.s.-1.25-treated endothelial cells. Furthermore, only parent sulfated polysaccharides from L. saccharina (L.s.-P) and its fraction L.s.-1.25 were powerful inhibitors of basic fibroblast growth factor (bFGF) induced pathways. Consistently, the L.s.-1.25 fraction as well as L.s.-P successfully interfered with fibroblast binding to human bFGF. The incorporation of L.s.-P or L.s.-1.25, but not L.s.-1.0 into Matrigel plugs containing melanoma cells induced a significant reduction in hemoglobin content as well in the frequency of tumor-associated blood vessels. Moreover, i.p. administrations of L.s.-1.25, as well as L.s.-P, but not L.s.-1.0, resulted in a significant reduction of tumor growth when inoculated into syngeneic mice. Finally, L.s.-1.25 markedly inhibited breast cancer cell adhesion to human platelet-coated surfaces. Thus, sulfated fucans are mainly responsible for the anti-inflammatory, anticoagulant, antiangiogenic, and antitumor activities of sulfated polysaccharides from L. saccharina brown seaweed
NMR and in silico studies of fucosylated chondroitin sulfate (fCS) and its interactions with selectins
This thesis describes structural studies on the interactions between the fucosylated
chondroitin sulfate (fCS) oligosaccharides and human proteins known as selectins. fCS is a
carbohydrate obtained from sea cucumbers, that can be classified as a branched
glycosaminoglycan (GAG). It has attracted much attention due to its anti-coagulant, anti-inflammatory,
antimetastatic and anti-HIV properties and its structure was previously
determined by NMR. Selectins constitute a family of proteins involved in cell adhesion
processes, such as inflammation, attachment of viral particles and migration of tumour cells.
fCS oligosaccharides have been shown to bind to selectins, which is likely a reason behind
their biological activity. However, the mechanism of this interaction is currently unknown.
The initial part of the thesis describes the experimental work on expression and purification
of the recombinant L- and P-selectin constructs in Pichia pastoris, Escherichia coli and HEK
293 cells. The aim of these experiments was to produce two constructs for each selectin, a
single domain construct, consisting of the C-type lectin domain only, and a double domain
construct, consisting of both the C-type lectin and the EGF-like domains. The intention was
that the recombinant proteins would be labelled with 13C and 15N to allow for the in-depth
structural NMR studies on the fCS-selectin interaction. Various experimental approaches
have been explored, including the use of different cell lines, modifications to construct design,
as well as alterations to expression and purification conditions. Although it was not possible
to produce soluble selectin constructs in either bacterial or yeast cells, protein expression
tests in HEK293 cells, performed in collaboration with the Oxford Protein Production facility
(OPPF), led to production of a soluble L-selectin construct, consisting of the L-selectin C-type
lectin domain.
The produced L-selectin construct, as well as two commercially available constructs of the Land
P-selectin extracellular domains, were used in the Saturation Transfer Difference (STD)
NMR experiments to provide new information about the nature of the fCS-selectin binding.
The STD experiments allowed to identify the regions within the fCS oligosaccharides that are
in direct contact with the protein and likely play an important role in this interaction.
Experiments on different protein constructs allowed the comparison of fCS binding to P-selectin
and to two different recombinant constructs of L-selectin. Results of these studies
suggest that the binding occurs via a similar mechanism for both L- and P-selectins and that
the fCS oligosaccharides bind to one-domain L-selectin construct with similar affinity as to a
larger construct, consisting of the entire extracellular region of the protein.
Alongside the experimental work, theoretical in silico studies on the fCS-selectin binding
were undertaken as part of this project. The existing X-ray structures of selectin complexes
were subjected to Molecular Dynamics (MD) simulations, which allowed to explore the
dynamic behaviour of E-selectin upon binding to sialyl Lewis x (sLex). It was found that sLex
forms a more favourable interaction with the extended conformation of E-selectin and that
the protein in this conformation is characterised by a high degree of interdomain flexibility,
with a new type of interdomain movement observed in the MD studies on this complex.
In further in silico studies, the fCS oligosaccharides were docked to the existing P-selectin
structures. The docking tests were performed on the computationally produced fCS
trisaccharides with fucose branches either 2,4 or 3,4-sulfated. Results were evaluated with
MD simulations and analysed in the light of current knowledge of selectin-ligand binding and
the STD NMR experimental results. The in silico studies allowed to identify a subset of P-selectin
residues that are likely involved in the interaction with fCS oligosaccharides in vivo.
The conformational behaviour of P-selectin upon binding to fCS was also explored and it was
found that the interdomain hinge is flexible during this interaction and allows transition from
bent to extended conformational state.
Finally, a new NMR method was developed to facilitate the studies of complex carbohydrates,
incorporating the concepts of G-matrix Fourier Transform (GFT) NMR into 2D HSQC and 2D
HSQC-TOCSY experiments. The method allows to separate peaks in the regions of high
spectral overlap, providing information that can simplify the assignment process. The new
experiments facilitated the structural evaluation of a sample containing a mixture of
oligosaccharides resulting from the depolymerisation of fCS polysaccharide
Диагностика неатрофического антрального хеликобактер-ассоциированного гастрита у больных язвенной болезнью двенадцатиперстной кишки в сочетании с бронхиальной астмой с помощью тест-системы «Гастропанель»
This paper presents the results obtained by the investigation of morphological condition of a gastric mucosa and serum concentration of pepsinogen-I, pepsinogen-II, and gastrin-17, as well as H. pylori IgG antibodies using «Gastropanel» test system when examining patients suffering from a duodenal ulcer combined with bronchial asthma. It was reveled that the level of serum concentration is in close relation to gastritis activity and Helicjbacter pylori bacterization in the gastric mucosa, thus expanding the «Gastropanel» test system application for diagnosing not only atrophic gastritis, but also for helicobacter gastritis without evidence of atrophy.В статье представлены результаты изучения морфологического состояния слизистой оболочки желудка и сывороточных концентраций пепсиногена-I, пепсиногена-II, гастрина-17 и антител к Helicobacter pylori с использованием тест-системы «Гастропанель» у больных язвенной болезнью в сочетании с бронхиальной астмой. Выявлена взаимосвязь уровня сывороточных показателей с активностью гастрита и степенью обсемененности Helicobacter pylori слизистой оболочки желудка, что позволяет расширить область применения данной тест-системы для диагностики у больных не только атрофического гастрита, но и хеликобактерного гастрита без признаков атрофии