Ecological and biological features of Triglochin maritima L. in the biotopes of the littoral zone with different degree of flooding on the coast of the White Sea

The study of Triglochin maritima L. was carried out on the Pomor (western) coast of the White Sea, in the Republic of Karelia (64°22'81"N, 35°93'14"E). Morphological analysis of aboveground and underground parts of the clones was performed on virginal plants. Anatomical analysis of leaf sheaths of the current year shoots, rhizomes and adventitious roots was carried out. The viability of pollen was assessed by determining the relative share of normally developed and malformed pollen grains. The content of heavy metals was determined in the soil, sea water and plant samples. The study was carried out on a model transect in the littoral zone on three test plots representing the lower littoral; the middle and the upper littoral zones. Adaptation to wave and storm impact was manifested in a well-developed system of underground organs. In the lower littoral, underground part surpasses the aboveground vegetative organs in terms of the mass and the formation of mechanical tissues. This allows the plants to anchor stronger in the substrate. Pollen analysis confirmed the adaptability of T. maritima plants to the conditions of the lower littoral by a high percentage of normal and, consequently, fertile pollen, which ensures sexual reproduction of the species. T. maritima can be considered as a Fe hyperaccumulator as the plant accumulates very high levels of Fe (22–34 g kg-1), especially in the lower and middle littoral zones, both in underground and aboveground organs. The ability of T. maritima plants to actively deposit metals was revealed on the basis of the coefficient of biological absorption of metals and makes it possible to suggest potential possibility of using the species in phytoremediation technologies on coastal territories

The heating rate influence on the elastic modulus temperature dependence of a corrosion-resistant nickel alloy

The temperature dependence of the elastic modulus of nickel-chromium-molybdenum alloy C4 was investigated by the method of dynamic mechanical analysis. At all heating rates, an abnormal increase in the elastic modulus is observed upon heating in the temperature range of 200-300 °C. It is shown that an increase in the heating rate shifts the beginning of the observed effect to the region of higher temperatures. The temperature anomaly in the elastic modulus of the C4 alloy is explained from the standpoint of the formation of a short-range order in a solid solution. The thermodynamically equilibrium temperature of the "disorder - short-range order" transition in C4 alloy is determined to be 205 °C. © Published under licence by IOP Publishing Ltd

QED cascades induced by circularly polarized laser fields

The results of Monte-Carlo simulations of electron-positron-photon cascades initiated by slow electrons in circularly polarized fields of ultra-high strength are presented and discussed. Our results confirm previous qualitative estimations [A.M. Fedotov, et al., PRL 105, 080402 (2010)] of the formation of cascades. This sort of cascades has revealed the new property of the restoration of energy and dynamical quantum parameter due to the acceleration of electrons and positrons by the field and may become a dominating feature of laser-matter interactions at ultra-high intensities. Our approach incorporates radiation friction acting on individual electrons and positrons.Comment: 13 pages, 10 figure

Fulminant invasive group A streptococcal infection in children

Group A streptococcal infections dominate among invasive streptococcal infections, with the major causative agent, Streptococcus pyogenes, being quite stable in the environment and bearing a large number of chromosome encoded pathogenicity factors or transmitted by horizontal transfer through bacteriophages. Different genetic variants of S. pyogenes can have a different set of pathogenicity factors able to change during pathogen evolution and determine virulence level for specific isolate. With a short incubation period, the disease can proceed with developing invasive infection and toxic shock syndrome with unfavorable outcome within 7 days from disease onset. The purpose of this article is to increase the doctors’ alertness to early recognition and diagnosis, which directly affects adequate treatment in a timely manner and disease outcome. The data on streptococcal morbidity in Russia and worldwide, review of laboratory diagnostic methods and pathogen genetic typing are presented. The maximum number of cases of streptococcal septicemia in Russia was registered in 2022, which accounted for 69% of all cases during the 2014–2022 observation period. The article also describes two clinical cases of fulminant invasive group A streptococcal infection in children with symptoms of acute respiratory viral infections at the onset of the disease. The results of various laboratory diagnostics methods verifying the diagnosis are presented. The genetic characterization of microbial isolates was performed by deep DNA sequencing. In the biological material from patients (including autopsy in one case), S. pyogenes sequence type ST-28, serotypes emm-1.25 and emm-1.0 were identified. The increasing importance of invasive streptococcal infection for health care in Russia and other countries may be associated with a possible change in dominating S. pyogenes genetic variants. In this regard, the study on circulating S. pyogenes genotypes on an ongoing basis as part of surveillance of streptococcal infection and development of vaccine for specific prevention are required

Феномен подавления ДНК-метилтрансферазы 3А при формировании резистентного фенотипа в клетках рака молочной железы

Introduction. Rearrangement of molecular pathways and activation of bypass signaling determine the progression of tumor cell resistance to various drugs. Study of the common features of resistant formation mechanisms is essential for breast and other cancer beneficial treatments.Materials and methods. The present work was performed on estrogen receptor α ERα-positive (ERα – estrogen receptor α) McF-7 breast cancer cells, established sublines resistant to the mTOR inhibitor rapamycin or antiestrogen tamoxifen, and ERα-negative MDA-MB-231 breast cancer cells. Methods used include MTT test, transient transfection, immunoblotting, real-time polymerase chain reaction and methylation analysis by bisulfite pyrosequencing.Results. We have shown that the resistance of breast cancer cells to targeted and hormonal drugs is associated with the suppression of DNA methyltransferase 3A (DNMT3A) and respective changes in DNA methylation; DNMT3A knockdown results in the partial resistance to both drugs demonstrating the pivotal role of DNMT3A suppression in the progression of cell resistance.Conclusion. Totally, the results obtained highlight the possible mechanism of tumor cell resistance to targeting/hormonal drugs based on the deregulation of DNMTs expression and demonstrate  direct connection between DNMT3A suppression and resistance progression.Введение. Переключение сигнальных путей и активация параллельных сигнальных каскадов относятся к ключевым факторам, определяющим развитие резистентности опухолевых клеток, и изучение механизмов подобной реаранжировки является одной из актуальных задач современной онкологии.Материалы и методы. Настоящая работа выполнена на ERα-положительных  (ERα – эстрогеновый рецептор α) клетках рака молочной железы MCF-7 и полученных из них сублиниях, устойчивых к ингибитору mTOR рапамицину или антиэстрогену тамоксифену, а также на ERα-отрицательных клетках рака молочной железы MDA-MB-231. Используемые методы включают тест МТТ, транзиторную трансфекцию, иммуноблоттинг, полимеразную цепную реакцию в реальном времени и анализ метилирования с помощью бисульфитного пиросеквенирования.Результаты. Мы показали, что резистентность клеток рака молочной железы к таргетным и гормональным препаратам связана с подавлением ДНК-метилтрансферазы 3А (DNMT3A) и соответствующими изменениями в метилировании ДНК. Нокдаун DNMT3A приводит к частичной резистентности к обоим препаратам, что демонстрирует ключевую роль подавления DNMT3A в развитии резистентности опухолевых клеток.Заключение. В целом, полученные результаты свидетельствуют о возможном механизме формирования устойчивости опухолевых клеток к таргетным/гормональным препаратам, основанном на дерегуляции экспрессии DNMT, и демонстрируют прямую связь между подавлением DNMT3A и развитием резистентности

Vascular control parameters and gene polymorphism associated with cardiovascular risk in young and relatively healthy individuals

Aim. To study the relationship of polymorphism of APOC3, PON1, AGT, AGTR1 genes and Vascular control parameters (blood pressure — BP and heart rate — HR) when performing an orthostatic test in young individuals.Material and methods. The study involved 75 relatively healthy Caucasian volunteers aged 20-25 years. The exclusion criterion was the presence of cardiovascular and central nervous pathologies. Vascular control was assessed by conducting an active orthostatic test. Identification of gene polymorphism was carried out by the method of deoxyribonucleic acid pyrosequencing.Results. Persons with the presence of the risk C allele of the A1666C A>C polymorphism of the AGTR1 gene have a lower heart rate in the prone position. The pulse pressure (PP) of these persons in the first minute after the rise remained at higher values. The highest levels of PP in the first minute as well as heart rate were observed in individuals whose genotype simultaneously contains the risk allele of the A1666C A>C polymorphism of the AGTR1 gene and T207M C>T polymorphism of the AGT gene. After 1 min of orthostasis in individuals carrying the mutant allele of the A1666C A>C polymorphism of the AGTR1 gene diastolic blood pressure (DBP) increased lesser, and the pulse pressure decreased “weaker” in relation to the initial values. The presence of the M268T T>C polymorphism of the AGT gene in the genotype was associated with a less high systolic blood pressure (SBP) at the first minute of orthostasis, as well as a less significant increase in DBP. Persons whose genotype contains the T allele of the L55M A>T polymorphism of the PON1 gene had a lower SBD and PP in the prone position. The presence in the genotype of the T allele of the -482 C>T polymorphism of the APOC3 gene is associated with lower rates of DBP in the prone position and SBP on the first minute after the rise. Also these individuals showed a more pronounced heart rate increase after the rise.Conclusion. There is a significant relationship between the studied polymorphic variants of the APOC3, PON1, AGT, AGTR1 genes and vascular control parameters in the context of orthostasis. It may be a predictor of early development of arterial hypertension

THE GENES ASSOCIATED WITH LIPID METABOLISM DISORDERS AND WITH BLOOD PRESSURE REGULATION, AND PSYCHOVEGETATIVE CHANGES IN THE YOUNG ALMOST HEALTHY PERSONS

Aim. To assess the  relation of polymorphism of the  genes  APOC3, PON1, AGT, AGTR1 and psychovegetative disorders in young, relatively healthy persons.Material and methods. Totally, 75 healthy volunteers included, white race, aged 20-25 y.o. Psychovegetative status was assessed with tests for panic  attacks  revealing,  anxiety level assessment,  as  with the questionnaire  for vegetovascular  dystony. The inclusion criteria was organic  pathology  of  cardiovascular  and  central  nervous  system. Genes polymorphism was identified with the method of pyrosequencing of  desoxyribonucleic  acid  with  the   genetic   analysis  equipment “PyroMark Q24”Results. The presence of vegetovascular  dystony, panic attacks  and increased  level of anxiety was mostly associated with the presence of T polymorphism -482 C>T gene APOC3, allele М polymorphism L55M А>Т gene PON1 and allele А — polymorphism А1666С А>С gene AGTR1. Conclusion. There is relation of genes  polymorphism playing role in lipids metabolism and arterial pressure regulation, with psychovegetative status of the young, relatively healthy persons

Which Comes First, Nonalcoholic Fatty Liver Disease or Arterial Hypertension?

Non-alcoholic fatty liver disease (NAFLD) and arterial hypertension (AH) are widespread noncommunicable diseases in the global population. Since hypertension and NAFLD are diseases associated with metabolic syndrome, they are often comorbid. In fact, many contemporary published studies confirm the association of these diseases with each other, regardless of whether other metabolic factors, such as obesity, dyslipidemia, and type 2 diabetes mellites, are present. This narrative review considers the features of the association between NAFLD and AH, as well as possible pathophysiological mechanisms