Properties of the VT1-0 titanium surface modified by a pulsed ion beam

The physicomechanical properties of the VT1-0 titanium surface modified by a pulsed carbon ion beam at a pulse duration of 80 ns, an energy of 200 keV, a current density of 120 A/cm2, an energy density of 1.92 J/cm2, and various numbers of pulses (four regimes) are studied. Irradiation by the beam leads to hardening of a 1.8-μm-thick surface layer in titanium, a decrease in the hydrogen sorption rate, a decrease in the grain size, and the formation of twins

Site-Selective Artificial Ribonucleases: Oligonucleotide Conjugates Containing Multiple Imidazole Residues in the Catalytic Domain

Design of site-selective artificial ribonucleases (aRNases) is one of the most challenging tasks in RNA targeting. Here, we designed and studied oligonucleotide-based aRNases containing multiple imidazole residues in the catalytic part and systematically varied structure of cleaving constructs. We demonstrated that the ribonuclease activity of the conjugates is strongly affected by the number of imidazole residues in the catalytic part, the length of a linker between the catalytic imidazole groups of the construct and the oligonucleotide, and the type of anchor group, connecting linker structure and the oligonucleotide. Molecular modeling of the most active aRNases showed that preferable orientation(s) of cleaving constructs strongly depend on the structure of the anchor group and length of the linker. The inclusion of deoxyribothymidine anchor group significantly reduced the probability of cleaving groups to locate near the cleavage site, presumably due to a stacking interaction with the neighbouring nucleotide residue. Altogether the obtained results show that dynamics factors play an important role in site-specific RNA cleavage. Remarkably high cleavage activity was displayed by the conjugates with the most flexible and extended cleaving construct, which presumably provides a better opportunity for imidazole residues to be correctly positioned in the vicinity of scissile phosphodiester bond

Involvement of Urokinase-Type Plasminogen Activator Receptor in the Formation of a Profibrotic Microenvironment in the Epicardial Region

The study of the mechanisms of development and progression of fibrosis is one of the key directions of modern cardiology. Our work suggests that the urokinase receptor (uPAR) is involved in the regulation of mesothelial cell activity and epicardial fibrosis development, which, when interacting with specific ligands and intermediate proteins, can activate intracellular signaling, trigger the cascade of proteolytic reactions, including local plasmin formation and activation of matrix metalloproteinases, providing matrix remodeling.Objective: to perform a comparative study of fibrogenic activity of the epicardium in the hearts of uPAR-/- and wild-type animals and evaluate the effect of cardiac microenvironment factors on the migration activity of epicardial mesothelial cells.Material and methods. We used histological and immunofluorescent staining, microarray analysis of proinflammatory cytokine levels, and a method for assessing the migratory properties of epicardial cells.Results. Results. We found that compared to wild-type animals, uPAR-/- animals show significant thickening of the epicardial area (2.46+0.77 (uPAR-/- mice) and 1.02+0.17 (Wt mice) relative units, P=0.033) accompanied by accumulation of extracellular matrix proteins. Deficiency of uPAR gene leads to formation of proinflammatory microenvironment in the heart (increased levels of proinflammatory factors such as IL-1, IL-13, IL-17, RANTES and MIP1), increased migratory activity of epicardial mesothelial cells, accumulation of TCF21+fibroblast/myofibroblast precursors (29.8+13.7 (uPAR-/- mouse) and 3.03+0.8 (Wt mouse) cells per visual field,P=0.02), as well as development of subepicardial fibrosis.Conclusion. These findings suggest that uPAR is a promising candidate for the developing targeted agents to prevent the development and progression of cardiac fibrosis

Right heart condition in patients with COVID-19 pneumonia

Aim. To assess right heart condition in patients with coronavirus disease 2019 (COVID-19) pneumonia.Material and methods. One hundred and five patients with COVID-19 pneumonia were divided into 3 groups depending on the involvement of lung parenchyma: group I — 0-25%, II — 25-50%, III — 50-75%. The clinical status of patients was assessed using the NEWS2 and SHOKS-COVID scales. A complete blood count and biochemical blood tests were performed to determine the level of N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin I. Echocardiography was performed to assess the right heart structural, hemodynamic and functional parameters.Results. In patients with COVID-19 pneumonia, with an increase in lung parenchyma involvement, the intensity of systemic inflammatory response increased: C-reactive protein, group I — (4 [1,9; 35] mg/l), in III — (70,5 [33; 144] mg/l) (pI-III=0,012); myocardial stress marker level increased: NT-proBNP, group I — 77 [48; 150] ng/l, group III — 165 [100; 287] ng/l (pI-III=0,047). The dependence of NT-proBNP on C-reactive protein level was revealed (r=0,335, p=0,03). Intergroup comparison did not reveal significant differences between the main right heart functional parameters: TAPSE, Tei index (PW and TDI), FAC of the right ventricle (RV) (p>0,05). However, differences in the tricuspid annular peaks were found as follows: group I — 0,14 [0,12; 0,14] m/s, group II — 0,14 [0,12; 0,15] m/s, group III — 0,16 [0,14; 0,17] m/s (pI-II=0,012, pI-III=0,014) and RV global longitudinal strain: group I — 19,63±7,72%, group III — 27,4±5,93% (pI-III=0,014). The relationship between the RV global longitudinal strain and SHOKS-COVID score was confirmed (r=0,381; p=0,024).Conclusion. Patients with COVID-19 pneumonia showed no signs of right heart dysfunction. The development of RV hyperfunction was noted. Most likely, this is a compensatory mechanism in response to acute RV afterload. NT-proBNP increase under conditions of an inflammatory response may indicate myocardial stress. The results obtained allow to expand our understanding of the right heart condition in patients with COVID-19 pneumonia

Биологические свойства грамнегативных бактерий, верифицированных в моче пациенток с рецидивирующей неосложненной инфекцией нижних мочевых путей

Uncomplicated infections of the lower urinary tract are more often recorded in women and are characterized by recurrent severe course. The lack of effective approaches to the management of this cohort of patients and the insufficient knowledge of the qualitative characteristics of uropathogens hinder the successful treatment of these infections. The purpose of this project is to study the biological properties of representatives of Gram-negative bacteria isolated from the urine of patients with recurrent uncomplicated lower urinary tract infection at various levels of bacteriuria.We present here the results of the one-stage cohort study of 62 patients 20-50 years old with recurrent uncomplicated lower urinary tract infection. The level of bacteriuria, genes of virulence factors, hemolytic, adhesive and anti-lysozyme activities were determined for the Gram-negative bacteria isolated from the urine of patients.Representatives of Gram-negative microorganisms (62 strains) were isolated from the urine of all patients. Their bacteriuria levels ranged from 102 to 108 CFU/ml. A wide range of the virulence factor genes with the prevalence of papGII, feoB, fyuA, were found in all strains regardless of the degree of bacteriuria. Twenty significant (p<0.05) coefficients of mutual contingency between different pairs of genes were found. We found that the hemolytic activity of Enterobacteriaceae is statistically significantly associated with papA, feoB, fyuA, kpsMII, and usp, while the anti-lysozyme activity is associated with papA, afa, and usp.The detection of genotypic and some phenotypic traits expressed in various variations in all Gram-negative bacteria regardless of their bacteriuria levels creates a potential risk for recurrent of the lower urinary tract infection. Consequently, even the minimal levels of bacteriuria become clinically significant. Therefore, in bacteriological diagnostics it is necessary to determine all levels of bacteriuria, including the minimum level (102 CFU/ml), since isolated microorganisms at this level have not only adhesive and anti-lysozyme activities, but also contain genes encoding the virulence factors. Неосложненные инфекции нижних мочевых путей чаще регистрируются у женщин и характеризуются рецидивирующим тяжелым течением. Отсутствие эффективных подходов по ведению данной когорты пациенток и недостаточная изученность качественных характеристик уропатогенов препятствуют успешному лечению этих инфекций. Цель настоящего исследования — изучить биологические свойства представителей грамнегативной микробиоты, выделенной из мочи паци­енток с рецидивирующей неосложненной инфекцией нижних мочевых путей, при различных уровнях бактериурии.Проведено когортное одномоментное исследование 62 пациенток в возрасте 20–50 лет с рецидивирующей неосложнен­ной инфекцией нижних мочевых путей. У грамнегативных бактерий, выделенных из мочи пациенток, определяли уровень бактериурии, гены факторов вирулентности, гемолитическую, адгезивную и антилизоцимную активности.У всех пациенток из мочи выделены представители грамнегативных микроорганизмов (62 штамма). Уровни бактери­урии колебались от 102 до 108 КОЕ/мл. У всех штаммов обнаружены гены факторов вирулентности в широком диапазоне с превалированием papGII, feoB, fyuA независимо от степени бактериурии. Обнаружено 20 достоверных (p<0.05) коэффи­циентов взаимной сопряженности между различными парами генов. Гемолитическая активность энтеробактерий значимо связана с papA, feoB, fyuA, kpsMII и usp, антилизоцимная – с papA, afa и usp.Таким образом, наличие генотипических и некоторых фенотипических признаков в различных вариациях экспрессии у всех представителей грамнегативных бактерий при всех уровнях бактериурии создает потенциальный риск развития очередного рецидива инфекции нижних мочевых путей. Поэтому даже минимальные уровни бактериурии являются кли­нически значимыми. Таким образом, при бактериологической диагностике необходимо определять все уровни бактери­урии, включая минимальный (102 КОЕ/мл), так как выделенные микроорганизмы при данном уровне обладают не только адгезивной и антилизоцимной активностями, но и имеют гены факторов вирулентности

Systematic Genetic Screens Reveal the Dynamic Global Functional Organization of the Bacterial Translation Machinery

Bacterial protein synthesis is an essential, conserved, and environmentally responsive process. Yet, many of its components and dependencies remain unidentified. To address this gap, we used quantitative synthetic genetic arrays to map functional relationships among >48,000 gene pairs in Escherichia coli under four culture conditions differing in temperature and nutrient availability. The resulting data provide global functional insights into the roles and associations of genes, pathways, and processes important for efficient translation, growth, and environmental adaptation. We predict and independently verify the requirement of unannotated genes for normal translation, including a previously unappreciated role of YhbY in 30S biogenesis. Dynamic changes in the patterns of genetic dependencies across the four growth conditions and data projections onto other species reveal overarching functional and evolutionary pressures impacting the translation system and bacterial fitness, underscoring the utility of systematic screens for investigating protein synthesis, adaptation, and evolution

Germ Warfare in a Microbial Mat Community: CRISPRs Provide Insights into the Co-Evolution of Host and Viral Genomes

CRISPR arrays and associated cas genes are widespread in bacteria and archaea and confer acquired resistance to viruses. To examine viral immunity in the context of naturally evolving microbial populations we analyzed genomic data from two thermophilic Synechococcus isolates (Syn OS-A and Syn OS-B′) as well as a prokaryotic metagenome and viral metagenome derived from microbial mats in hotsprings at Yellowstone National Park. Two distinct CRISPR types, distinguished by the repeat sequence, are found in both the Syn OS-A and Syn OS-B′ genomes. The genome of Syn OS-A contains a third CRISPR type with a distinct repeat sequence, which is not found in Syn OS-B′, but appears to be shared with other microorganisms that inhabit the mat. The CRISPR repeats identified in the microbial metagenome are highly conserved, while the spacer sequences (hereafter referred to as “viritopes” to emphasize their critical role in viral immunity) were mostly unique and had no high identity matches when searched against GenBank. Searching the viritopes against the viral metagenome, however, yielded several matches with high similarity some of which were within a gene identified as a likely viral lysozyme/lysin protein. Analysis of viral metagenome sequences corresponding to this lysozyme/lysin protein revealed several mutations all of which translate into silent or conservative mutations which are unlikely to affect protein function, but may help the virus evade the host CRISPR resistance mechanism. These results demonstrate the varied challenges presented by a natural virus population, and support the notion that the CRISPR/viritope system must be able to adapt quickly to provide host immunity. The ability of metagenomics to track population-level variation in viritope sequences allows for a culture-independent method for evaluating the fast co-evolution of host and viral genomes and its consequence on the structuring of complex microbial communities

Сравнительный анализ применения тоцилизумаба при тяжелых COVID-19-ассоциированных пневмониях у пациентов разных возрастных групп

According to accumulated clinical data, one of the causes of severe damage to lung epithelial cells associated with SARS-CoV-2 (2019-nCoV) is an acute, timely underestimated "cytokine storm" (cytokine cascade, hypercytokinaemia) with characteristic signs of an expressed hyper-inflammatory syndrome with subsequent polyorganic failure. The study presents the results of the analysis of the effectiveness of tocilizumab therapy (TCZ) in patients (n = 181) of different age groups with developed pneumonia caused by SARS-CoV-2. The aim of the study was to evaluate the effectiveness of TCZ therapy in patients of different age groups with developed pneumonia in the frame of COVID-19. Methods. Patients (n = 181) with community-acquired pneumonia caused by coronavirus SARS-CoV-2 are included in a one-center, non-randomized, prospective study to evaluate the effectiveness of TCZ therapy conducted at the State Public Health Institution "City Clinical Hospital No.52" of the Moscow City Health Department. Patients were divided into 3 age subgroups – up to 50 years, 50–70 years and over 70 years. Patients with community-acquired SARS-CoV-2-induced pneumonia receiving non-invasive oxygen support and patients who had artificial lung ventilation (ALV) were given a single dose of 400 mg of TCZ in addition to basic therapy. Results. There are no significant differences between age groups in the severity of pneumonia according to the data of the computed tomography (CT), however, a more severe condition and a higher mortality rate (p < 0.001) were reliably observed in patients over 70 age compared to the other age groups. After TCZ treatment in patients of each age group, the severity of the condition assessed on the National Early Warning Score (NEWS2) has been significantly reduced compared to the baseline. Conclusion. According to the data of the pilot study the efficacy and safety of TCZ in patients of all presented age groups with COVID-associated pulmonary tissue lesion and signs of "cytokine storm" was demonstrated. At the same time, patients up to 50 years after the therapy of TCZ managed to achieve greater clinical efficiency compared to patients in other groups. According to the severity of the state and laboratory criteria, the lowest clinical efficacy of TCZ therapy was observed in patients over 70 years of age; as a consequence, the highest mortality rate was observed in the same group. At the same time, the TCZ therapy has not had a positive impact on the change of laboratory values and the severity of the disease in case of unfavorable outcome. Согласно накопленным клиническим данным, одной из причин тяжелых повреждений клеток эпителия легких, ассоциированных с SARS-CoV-2 (2019-nCoV), является острый, вовремя недооцененный синдром «цитокинового шторма» (цитокиновый каскад, гиперцитокинемия) с характерными признаками выраженного гипервоспалительного синдрома с последующей полиорганной недоста - точностью. В работе представлены результаты анализа эффективности терапии тоцилизумабом (ТЦЗ) у пациентов (n = 181) разных возрастных групп с развившейся пневмонией в рамках COVID-19. Целью исследования явилась оценка эффективности терапии ТЦЗ у пациентов разных возрастных групп с развившейся пневмонией, вызванной SARS-CoV-2. Материалы и методы. В одноцентровом нерандомизированном проспективном исследовании оценки эффективности терапии ТЦЗ, проведенном на базе Государственного бюд жетного учреждения здравоохранения «Городская клиническая больница № 52» Департамента здравоохранения города Мос - квы, приняли участие пациенты (n = 181) с внебольничной пневмонией, вызванной коронавирусом SARS-CoV-2. Больные были распределены в 3 возрастные подгруппы: до 50 лет, 50–70 лет, старше 70 лет. Пациентам с внебольничной пневмонией, вызванной SARS-CoV-2, получающим неинвазивную кислородную поддержку, и больным, у которых проводилась искусственная вентиляция легких (ИВЛ), в до полнение к основной терапии назначен ТЦЗ однократно в дозе 400 мг. Результаты. Достоверных различий между возрастными группами по тяжести пневмонии по данным компьютерной томографии (КТ) не выявлено, однако отмечено достоверно более тяжелое состояние и более высокий уровень смертности (p < 0,001) у больных старше 70 лет по сравнению с остальными возрастными группами. После терапии ТЦЗ у больных каждой из возрастных групп тяжесть состояния, оцененная по шкале National Early Warning Score (NEWS2), достоверно снизилась по сравнению с исходными показателями. Заключение. По данным пилотного исследования продемонстрирована эффективность и безопасность применения ТЦЗ у пациентов всех представленных возрастных групп с COVID-ассоциированным повреждением легочной ткани и признаками «цитокинового шторма». При этом у пациентов до 50 лет после терапии ТЦЗ удалось добиться бόльшей клинической эффективности по сравнению с больными остальных групп. По степени тяжести состояния и лабораторным критериям самая низкая клиническая эффективность терапии ТЦЗ отмечена у пациентов старше 70 лет; как следствие, в этой же группе отмечен самый высокий уровень смертности. При этом в случае неблагоприятного исхода терапия ТЦЗ не оказывала положительного влияния на изменение лабораторных показателей и степень тяжести заболевания.