Foci Formation Research Articles

FBW7/GSK3β mediated degradation of IGF2BP2 inhibits IGF2BP2-SLC7A5 positive feedback loop and radioresistance in lung cancer

BackgroundThe development of radioresistance seriously hinders the efficacy of radiotherapy in lung cancer. However, the underlying mechanisms by which radioresistance occurs are still incompletely understood. The N6-Methyladenosine (m6A) modification of RNA is involved in cancer progression, but its role in lung cancer radioresistance remains elusive. This study aimed to identify m6A regulators involved in lung cancer radiosensitivity and further explore the underlying mechanisms to identify therapeutic targets to overcome lung cancer radioresistance.MethodsBioinformatic mining was used to identify the m6A regulator IGF2BP2 involved in lung cancer radiosensitivity. Transcriptome sequencing was used to explore the downstream factors. Clonogenic survival assays, neutral comet assays, Rad51 foci formation assays, and Annexin V/propidium iodide assays were used to determine the significance of FBW7/IGF2BP2/SLC7A5 axis in lung cancer radioresistance. Chromatin immunoprecipitation (ChIP)-qPCR analyses, RNA immunoprecipitation (RIP) and methylated RNA immunoprecipitation (MeRIP)-qPCR analyses, RNA pull-down analyses, co-immunoprecipitation analyses, and ubiquitination assays were used to determine the feedback loop between IGF2BP2 and SLC7A5 and the regulatory effect of FBW7/GSK3β on IGF2BP2. Mice models and tissue microarrays were used to verify the effects in vivo.ResultsWe identified IGF2BP2, an m6A “reader”, that is overexpressed in lung cancer and facilitates radioresistance. We showed that inhibition of IGF2BP2 impairs radioresistance in lung cancer both in vitro and in vivo. Furthermore, we found that IGF2BP2 enhances the stability and translation of SLC7A5 mRNA through m6A modification, resulting in enhanced SLC7A5-mediated transport of methionine to produce S-adenosylmethionine. This feeds back upon the IGF2BP2 promoter region by further increasing the trimethyl modification at lysine 4 of histone H3 (H3K4me3) level to upregulate IGF2BP2 expression. We demonstrated that this positive feedback loop between IGF2BP2 and SLC7A5 promotes lung cancer radioresistance through the AKT/mTOR pathway. Moreover, we found that the ubiquitin ligase FBW7 functions with GSK3β kinase to recognize and degrade IGF2BP2.ConclusionsCollectively, our study revealed that the m6A “reader” IGF2BP2 promotes lung cancer radioresistance by forming a positive feedback loop with SLC7A5, suggesting that IGF2BP2 may be a potential therapeutic target to control radioresistance in lung cancer.

Possibilities of Therapeutic Angiogenesis in Patients with Critical Lower Limb Ischemia

Two clinical observations of effective treatment of patients with critical ischemia of the lower extremities using plasma-free lysate autologous platelets. Both patients were male, 73 and 53 years old. Both were diagnosed with total damage to the arteries of the infrainguinal zone. One of them had previously undergone endarterectomy from the femoral artery with subsequent thrombosis. After examination and joint discussion with x-ray endovascular surgeons, they were found inoperable. Due to the ineffectiveness of standard conservative therapy, the patient was offered local administration of plasma-free lysate autologous platelets. After receiving written informed consent, the procedure for collecting venous blood and obtaining plasma-free lysate autologous platelets and the introduction of this drug into the muscles of the leg from the side of ischemia according to the original method. The method for assessing microcirculation was three-phase scintigraphy : before treatment, both patients showed a significant decrease in the inclusion of osteotropic radiopharmaceutical in the soft tissues of the legs. For areas of radiopharmaceutical hyperfixation, relative accumulation coefficients were calculated: for one patient, the calculation results demonstrated the formation of foci of aseptic necrosis. When patients were re-hospitalized after 6 months, there was an improvement in local status and relief of rest pain. According to scintigraphy, a significant improvement in microcirculation was noted; no foci of aseptic necrosis were identified. Thus, the use of plasma-free lysate autologous platelets in combination with complex conservative therapy has demonstrated positive results; this method can be considered as an alternative revascularization ischemic limb.

Role of C9orf72 hexanucleotide repeat expansions in ALS/FTD pathogenesis.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are progressive neurological disorders that share neurodegenerative pathways and features. The most prevalent genetic causes of ALS/FTD is the GGGGCC hexanucleotide repeat expansions in the first intron region of the chromosome 9 open reading frame 72 (C9orf72) gene. In this review, we comprehensively summarize the accumulating evidences elucidating the pathogenic mechanism associated with hexanucleotide repeat expansions in ALS/FTD. These mechanisms encompass the structural polymorphism of DNA and transcribed RNA, the formation of RNA foci via phase separation, and the cytoplasmic accumulation and toxicities of dipeptide-repeat proteins. Additionally, the formation of G-quadruplex structures significantly impairs the expression and normal function of the C9orf72 protein. We also discuss the sequestration of specific RNA binding proteins by GGGGCC RNA, which further contributes to the toxicity of C9orf72 hexanucleotide repeat expansions. The deeper understanding of the pathogenic mechanism of hexanucleotide repeat expansions in ALS/FTD provides multiple potential drug targets for these devastating diseases.

On the Weather Factors which Cause Outbreaks of Foliophagous Insects (on the Example of Black-veined White Aporia crataegi (L.) (Lepidoptera, Pieridae) in the Urals

On the example of the outbreak foci of black-veined white, that sprung up in the Urals in 2020, is shown how outbreak foci of the pest begin to develop. Besides in the article for the fi rst time the method of quantitative assessment of average span time during which occur formation of the outbreak foci of black-veined white and pine looper Bupalus piniarius (L.) is described. It is shown that outbreak foci of the both species come into being during interval of time no more than 1 hour. Average data of the black-veined white and pine looper outbreak foci formation in the south of Sverdlovsk region are 13 and 14 June accordingly.

Mechanisms of RNF168 nucleosome recognition and ubiquitylation

RNF168 plays a central role in the DNA damage response (DDR) by ubiquitylating histone H2A at K13 and K15. These modifications direct BRCA1-BARD1 and 53BP1 foci formation in chromatin, essential for cell-cycle-dependent DNA double-strand break (DSB) repair pathway selection. The mechanism by which RNF168 catalyzes the targeted accumulation of H2A ubiquitin conjugates to form repair foci around DSBs remains unclear. Here, using cryoelectron microscopy (cryo-EM), nuclear magnetic resonance (NMR) spectroscopy, and functional assays, we provide a molecular description of the reaction cycle and dynamics of RNF168 as it modifies the nucleosome and recognizes its ubiquitylation products. We demonstrate an interaction of a canonical ubiquitin-binding domain within full-length RNF168, which not only engages ubiquitin but also the nucleosome surface, clarifying how such site-specific ubiquitin recognition propels a signal amplification loop. Beyond offering mechanistic insights into a key DDR protein, our study aids in understanding site specificity in both generating and interpreting chromatin ubiquitylation.

Pathomorphological changes in the organs in aspergillosis in the shouter swan (clinical case)

Consideration and analysis of diseases of wild bird species is complicated, especially those listed in the Red Book. This work aimed to identify the pathomorphological features of the manifestation of aspergillosis in the mute swan and to assess the impact of this disease on the microbiocenosis of the lungs and the morphological structure of organs without cavities. The scientific work was conducted at the Department of Anatomy and Physiology of the Federal State Budgetary Educational Institution of Higher Education of the State Agrarian University of the Northern Trans-Urals. The object of study was the internal organs of a mute swan delivered for a post-mortem autopsy to determine the cause of death of the bird. All internal organs were examined pathoanatomically, and morphometry was performed and carried out bacteriological and mycological studies of the lungs according to traditional methods in microbiological practice. Histological study of such internal organs as the liver, kidneys and spleen was carried out using the generally accepted method. As a result of the analyses, it was established that a characteristic feature of the pathomorphological manifestation of aspergillosis was a topical lesion of the respiratory system with the formation of multiple tumour-like foci of two types in the lungs anddestructive changes in the structure of the tissue of the liver, kidneys and spleen. Congestive venous hyperemia is expressed in all organs, which indicates chronic heart failure. In the liver and kidneys, there are pronounced signs of tissue necrosis, which is a sign of the toxic effects of this disease on the body. In the spleen of the mute swan, the growth of red pulp may indicate an increase in the functioning of the immune system in this pathology. Five types of microorganisms from different subkingdoms were isolated from the mute swan’s lungs. Taking into account the peculiarities of the development of pathological changes and the degree of priority of one or another type of microorganism in the formation of lung pathology in birds, it has been established that Aspergillus fumigatus is the leading pathogen in the development of pathological changes in the lungs of the mute swan.

Sfrp1 inhibits lung fibroblast invasion during transition to injury-induced myofibroblasts.

Fibroblast-to-myofibroblast conversion is a major driver of tissue remodelling in organ fibrosis. Distinct lineages of fibroblasts support homeostatic tissue niche functions, yet their specific activation states and phenotypic trajectories during injury and repair have remained unclear. We combined spatial transcriptomics, multiplexed immunostainings, longitudinal single-cell RNA-sequencing and genetic lineage tracing to study fibroblast fates during mouse lung regeneration. Our findings were validated in idiopathic pulmonary fibrosis patient tissues in situ as well as in cell differentiation and invasion assays using patient lung fibroblasts. Cell differentiation and invasion assays established a function of SFRP1 in regulating human lung fibroblast invasion in response to transforming growth factor (TGF)β1. We discovered a transitional fibroblast state characterised by high Sfrp1 expression, derived from both Tcf21-Cre lineage positive and negative cells. Sfrp1 + cells appeared early after injury in peribronchiolar, adventitial and alveolar locations and preceded the emergence of myofibroblasts. We identified lineage-specific paracrine signals and inferred converging transcriptional trajectories towards Sfrp1 + transitional fibroblasts and Cthrc1 + myofibroblasts. TGFβ1 downregulated SFRP1 in noninvasive transitional cells and induced their switch to an invasive CTHRC1+ myofibroblast identity. Finally, using loss-of-function studies we showed that SFRP1 modulates TGFβ1-induced fibroblast invasion and RHOA pathway activity. Our study reveals the convergence of spatially and transcriptionally distinct fibroblast lineages into transcriptionally uniform myofibroblasts and identifies SFRP1 as a modulator of TGFβ1-driven fibroblast phenotypes in fibrogenesis. These findings are relevant in the context of therapeutic interventions that aim at limiting or reversing fibroblast foci formation.

FANCA c.3624C>T (p.Ser1208=) is a hypomorphic splice variant associated with delayed onset of Fanconi anemia

AbstractFanconi anemia (FA) is a hereditary, DNA repair deficiency disorder caused by pathogenic variants in any 1 of 22 known genes (FANCA-FANCW). Variants in FANCA account for nearly two-thirds of all patients with FA. Clinical presentation of FA can be heterogeneous and include congenital abnormalities, progressive bone marrow failure, and predisposition to cancer. Here, we describe a relatively mild disease manifestation among 6 individuals diagnosed with FA, each compound heterozygous for 1 established pathogenic FANCA variant and 1 FANCA exon 36 variant, c.3624C>T. These individuals had delayed onset of hematological abnormalities, increased survival, reduced incidence of cancer, and improved fertility. Although predicted to encode a synonymous change (p.Ser1208=), the c.3624C>T variant causes a splicing error resulting in a FANCA transcript missing the last 4 base pairs of exon 36. Deep sequencing and quantitative reverse transcription polymerase chain reaction analysis revealed that 6% to 10% of the FANCA transcripts included the canonical splice product, which generated wild-type FANCA protein. Consistently, functional analysis of cell lines from the studied individuals revealed presence of residual FANCD2 ubiquitination and FANCD2 foci formation, better cell survival, and decreased late S/G2 accumulation in response to DNA interstrand cross-linking agent, indicating presence of residual activity of the FA repair pathway. Thus, the c.3624C>T variant is a hypomorphic allele, which contributes to delayed manifestation of FA disease phenotypes in individuals with at least 1 c.3624C>T allele.

ALK F1174S mutation impairs ALK kinase activity in EML4-ALK variant 1 and sensitizes EML4-ALK variant 3 to crizotinib.

To assess the influence of F1174S mutation on kinase activity and drug sensitivity of the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) fusion (EML4-ALK) variants 1 and 3. We constructed mammalian expression plasmids of both wildtype and F1174 mutant EML4-ALK variants 1 and 3, and then characterized them with cell models by performing immunoblotting, neurite outgrowth assay, focus formation assay as well as protein stability assay. Drug sensitivity to ALK tyrosine kinase inhibitors was also compared between wildtype and F1174 mutant EML4-ALK fusions. In addition, we characterized the effect of different F1174 kinase domain mutations in the context of EML4-ALK fusions. In contrast to the oncogenic ALK-F1174S mutation that has been reported to be activating in the context of full-length ALK in neuroblastoma, EML4-ALK (F1174S) variant 1 exhibits impaired kinase activity leading to loss of oncogenicity. Furthermore, unlike the previously reported F1174C/L/V mutations, mutation of F1174 to S sensitizes EML4-ALK variants 3a and 3b to crizotinib. These findings highlight the complexity of drug selection when treating patients harboring resistance mutations and suggest that the F1174S mutation in EML4-ALK variant 1 is likely not a potent oncogenic driver. Additional oncogenic driver or other resistance mechanisms should be considered in the case of EML4-ALK variant 1 with F1174S mutation.

Abstract B022: C11ORF68 is essential for γH2AX formation after replication stress

Abstract Introduction: Unresolved replication stress (RS) often leads to genomic instability – a feature of many diseases including cancer. RS can activate downstream DNA damage response (DDR) phenotypes such as phosphorylation of histone H2AX (γH2AX). Therefore, understanding the molecular foundation of DDR is crucial for identifying potential biomarkers or therapeutic targets. Our lab has identified an uncharacterized protein that is symmetrically dimethylated by PRMT5 under hydroxyurea (HU) induced RS. Therefore, we hypothesize that C11ORF68 is involved in the RS and DNA damage response. Materials and methods: RS and DNA damaging agents including HU and etoposide were used to induce RS or DNA damage in various cell lines. C11ORF68 was depleted using siRNA and dicer siRNA (dsiRNA) systems. Immunofluorescence and immunoblotting were used to evaluate DDR phenotypes. Results: One of the earliest phenomenon in DDR is phosphorylation of histone H2AX (γH2AX). Depletion of C11ORF68 under HU-induced RS reduced γH2AX foci formation as compared to cells treated with control siRNA or dsiRNA. Since HU affects cells entering S-phase, we evaluated if this is a cell cycle-related effect by using other DNA damaging agents that target cells in all phases of the cell cycle. Similarly, depletion of C11ORF68 under DNA damaging conditions showed reduced γH2AX foci formation. This may be due to a lack of upstream PIKK kinases activation as knockdown of C11ORF68 also attenuated phosphorylation of PIKKs important for H2AX phosphorylation after treatment with DNA damaging agents and RS-inducing agents. Conclusions: Our data suggests that C11ORF68 it appears to modulate early DDR even before H2AX phosphorylation and upstream PIKK activation. We are currently investigating if C11ORF68 is involved in initial events after DNA damage or RS such as PARylation events or MRN sensing of DNA breaks. Citation Format: Clarissa Chin Min Toh, Mai Phuong Hoang, Anand Jeyasekharan. C11ORF68 is essential for γH2AX formation after replication stress [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr B022.

Abstract A028: Alcohol induces DNA damage and genomic instability in MCF-7 breast cancer cells and primary mammary tissues

Abstract Alcohol consumption has been associated with increased breast cancer risk. Previous studies indicated that alcohol-induced DNA damage plays a central role in carcinogenesis. However, the underlying molecular mechanisms remain unclear. This study aimed to examine the effect of alcohol exposure on key DNA damage/repair pathways in both in vitro and in vivo settings. When MCF-7 breast cancer cells were exposed to 0.1 ~ 0.8% alcohol, the treatment induced concentration-dependent DNA damage, as indicated by the increased 8-OHdG (8-hydroxy 2 deoxyguanosine) production and p-H2AX foci formation. Signal transduction analysis showed that alcohol induced DNA damage signals, including p53, p21, E2F-1 and CHK1, and the markers in DNA repair pathways, including XLF, Rad50 and DNA-PK. p53 knockdown in MCF-7 cells resulted in enhanced DNA damage and DNA repair responses, which underscores the role of p53 in alcohol-induced cellular regulation. We also demonstrated that alcohol induces sister chromatid exchanges (SCEs) in MCF-7 cells, and ALDH2 knockout enhanced alcohol induced SCEs, which suggests that alcohol-induced acetaldehyde (AA) is a key mediator in this process. Moreover, we examined the DNA damage markers in mammary tissues of FVB/N mice exposed to alcohol and showed that alcohol exposure in vivo induced similar patterns of DNA damage and repair responses. Taken together, our data highlights the contribution of alcohol-induced DNA damage in cellular injury and the consequent tumorigenesis, which provide fundamental support for further studies on alcohol-induced DNA damage and carcinogenesis. Citation Format: Xiaohe Yang. Alcohol induces DNA damage and genomic instability in MCF-7 breast cancer cells and primary mammary tissues [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr A028.

The COVID-19 Epidemic Process in Long-Term Care Facilities in Moscow

Relevance. COVID-19 remains an urgent disease for long-term care institutions (LTCI), because local outbreaks of COVID-19 continue to be registered in 2022 and in 2023.Aims. To study the epidemic process of COVID-19 in LTCI (nursing homes, neuropsychiatric boarding schools) in Moscow for 2020–2022.Materials and methods. The analysis of the epidemic process of COVID-19 in LTCI was carried out for the period 2020–2022. Data of Automatic information system «Department of Registration and Accounting of Infectious Diseases was used: 5390 COVID-19 residents and employees of 28 institutions in Moscow and 3,239,617 residents of Moscow; 15 acts of epidemiological investigation of the focus of infectious disease in the period from 2020 to 2022.Results. In total, 9 increases in the incidence of COVID-19 were registered. The first rise was the most intense, which affected morbidity (81.14 per 1,000 beds per week), indicators of activity of epidemic foci (KO – 100%, IO – 21.08, R – 20.08), mortality (for 2020 – 32.6%). In the first rise of morbidity in nursing homes, there is a direct correlation of a high degree of connection with the morbidity of the population of Moscow (r = 0.906), and for subsequent rises there is a noticeable relationship (r = 0.580) at p<0.05. From 2 to 9 rises, the incidence tended to decrease. All the rises of COVID-19 occurred due to the formation of foci in institutions where the source of infection was employees. For 2020–2022, the proportion of severe cases of infection with a fatal outcome among residents ranged from 14.6 ±6.7% to 31.8 ± 6.5%.Conclusion. The analysis of the manifestations of the COVID-19 epidemic process in long-term care institutions in Moscow for 2020–2022 allowed us to distinguish two stages of morbidity.

Results of screening for antibodies to varicella-zoster virus in healthcare workers of a multidisciplinary hospital in Moscow

Introduction. Given the unfavorable epidemic situation with chickenpox and shingles in Russia, there is a high risk of virus introduction and spread in healthcare settings, including among medical staff who are not immune to varicella zoster virus (VZV).
 The objective of this study is to assess the immunity of employees of a multidisciplinary hospital in Moscow to VZV.
 Materials and methods. A selective screening study was carried out. Venous blood serum samples were taken from 1546 hospital employees as material for detection of IgG antibodies to VZV antigens using a commercial solid-phase enzyme immunoassay (ELISA) test system "Vecto VZV-IgG". All employees were questioned to obtain information about their infectious and vaccine history in relation to VZV.
 Results and discussion. Screening for antibodies to VZV in the hospital workers revealed that 6.3% of those workers are not immune to VZV. The proportion of seronegative individuals was the highest (12.6 ± 2.4%) in the age group of 29 years and younger. VZV seronegative healthcare workers were found in various departments, but the presence of non-immune individuals among the staff of the obstetrics and gynecology departments (6.5%) is of epidemiologic concern. The results of the survey showed that documented data on infection and vaccination history cannot be used to assess the protection of healthcare workers against VZV infection.
 Conclusion. The results of serologic screening for antibodies to VZV made it possible to identify a significant number of susceptible employees of the multidisciplinary hospital. In order to prevent the formation of multiple epidemic foci of varicella in medical organizations, it is advisable to include anti-VZV testing of medical staff in the state prevention programs with subsequent vaccination of non-immune individuals.

Phase separation of S-RNase promotes self-incompatibility in Petunia hybrida.

Self-incompatibility (SI) is an intraspecific reproductive barrier widely present in angiosperms. The SI system with the broadest occurrence in angiosperms is based on an S-RNase linked to a cluster of multiple S-locus F-box (SLF) genes found in the Solanaceae, Plantaginaceae, Rosaceae, and Rutaceae. Recent studies reveal that non-self S-RNase is degraded by the Skip Cullin F-box (SCF)SLF-mediated ubiquitin-proteasome system in a collaborative manner in Petunia, but how self-RNase functions largely remains mysterious. Here, we show that S-RNases form S-RNase condensates (SRCs) in the self-pollen tube cytoplasm through phase separation and the disruption of SRC formation breaks SI in self-incompatible Petunia hybrida. We further find that the pistil SI factors of a small asparagine-rich protein HT-B and thioredoxin h together with a reduced state of the pollen tube all promote the expansion of SRCs, which then sequester several actin-binding proteins, including the actin polymerization factor PhABRACL, the actin polymerization activity of which is reduced by S-RNase in vitro. Meanwhile, we find that S-RNase variants lacking condensation ability fail to recruit PhABRACL and are unable to induce actin foci formation required for pollen tube growth inhibition. Taken together, our results demonstrate that phase separation of S-RNase promotes SI response in P. hybrida, revealing a new mode of S-RNase action.

Near-field resonant microwave sensing in the diagnostics of bovine mastitis

The purpose of this work is to analyze the possibilities of evaluating the dielectric parameters of the mammary gland of cows in the diagnosis of mastitis. The study was performed on animals from a number of farms in the Nizhny Novgorod and Kirov regions. A total of 269 mature cows were examined, 185 of which were healthy, 53 individuals had subclinical mastitis, and 31 had a clinically manifested form of the disease. The animals were examined once, by instrumental analysis of the dielectric parameters of the tissues of each lobe of the udder of the animal. The study was carried out using a software and hardware complex, which makes it possible to evaluate the dielectric permittivity of a biological object by the method of near-field resonant microwave sensing. As a result of our research, we have for the first time formed a physiological “pattern” of the dielectric permeability of the skin and breast tissues of actively lactating cows, taking into account the features of the morphological structure of the udder at a significant depth of subsurface sounding (20 mm). It was found that the presence of a focus of inflammation (both in the form of subclinical and manifesting mastitis) leads to a significant increase in dielectric constant (by 12.4 and 26.9%, respectively). At the same time, in healthy cows, the hydration level of tissues of various udder lobes is almost uniform, as evidenced by the values of the dielectric gain coefficient close to one. In the case of the formation of a mastitis focus in one or some parts of the udder, uniformity is violated, and the dielectric constant gradient can be up to 31% with a corresponding increase in the developed coefficient.

Пространственно-временной анализ природно-очаговых заболеваний (сибирская язва) на территории Северо-Казахстанской области

The article presents the results of study of actual focal disease for the North Kazakhstan region – anthrax. The historically established livestock specialization and excessive concentration of livestock in a limited area (albeit short-term), the presence of favorable natural and landscape conditions for the preservation of the causative agent of anthrax infection (primarily the soil and climatic factor) led to the formation of numerous foci of this disease within the region. The questions of spatio-temporal manifestation and spread of anthrax infection on the territory of the region are considered. The retrospective analysis of the epizootic and epidemic processes of anthrax for 1938– 2022 was performed using archival, stock, and statistical materials. The study was carried out using GIS technologies, then a database, a series of electronic maps and a regional thematic geoinformation system “Anthrax in the North Kazakhstan region” were created. It has been determined that the greatest potential danger (epizootic and epidemic intensity) of anthrax manifestations is typical for the northern and central parts of the region. Within the boundaries of natural landscape units, the maximum risk of anthrax infection was recorded in the forest and steppe area and the valley of the river Ishim. Practical recommendations are proposed for improving measures aimed at preventing anthrax: annual full vaccination of farm animals, sanitary and epidemiological control over slaughtering points and the state of anthrax burials, establishing and maintaining a buffer zone when grazing livestock near stationary-unfavorable foci.

ИСТОРИЯ И ЭВОЛЮЦИЯ МЕТОДОВ НЕЙРОВИЗУАЛИЗАЦИИ В ЭПИЛЕПТОЛОГИИ

The article examines history of fundamental discoveries, methods and clinical achievements in neuroimaging, their contribution to the development of diagnosing, treatment and understanding of epilepsy etiology, also as part of International League Against Epilepsy’s research. In the early stages of its development, neuroimaging had advanced rapidly in the areas of cancer detection, pneumoencephalography, pneumomiography, ventriculography, linear tomography and selective angiography. The development of epileptology was greatly influenced by the use of computed tomography and magnetic resonance imaging, which made it possible to identify pathological lesions in a large number of patients with cryptogenic epilepsy, expand the indications for surgical treatment and improve understanding of the pathogenesis of pathological processes in the brain associated with seizure activity. In recent years, functional magnetic resonance imaging, magnetic resonance spectroscopy, positron emission tomography and single-photon emission computed tomography have become the focus of attention of researchers, which revealed a huge number of different structural changes of the brain tissue, which lie at the basis of the formation of the epileptic focus and lead to the development of focal epilepsy.

Radiosensitization of Osteosarcoma Cells Using the PARP Inhibitor Olaparib Combined with X-rays or Carbon Ions.

Objective: Osteosarcomas are derived from bone-forming mesenchymal cells that are insensitive to radiation. This study aimed to investigate the radiosensitization of osteosarcoma cells (U2OS and K7M2) using the PARP inhibitor olaparib combined with X-rays or carbon ions (C-ions). Methods: The effect of olaparib on the proliferation of osteosarcoma cells after irradiation was assessed using CCK-8 and clone formation assays. Cells were treated with olaparib and/or radiation and the effects of olaparib on the cell cycle and apoptosis were analysed by flow cytometry after 48h. Immunofluorescence was used to stain the nuclei, γ-H2AX, 53BP1, and Rad51 proteins, and the number of γ-H2AX, 53BP1, and Rad51 foci was observed under a fluorescence microscope. The effect of olaparib combined with radiation on double-stranded DNA breaks in osteosarcoma cells was evaluated. Results: At the same radiation dose, olaparib reduced the proliferation and colony formation ability of irradiated osteosarcoma cells (P < 0.05). Olaparib monotherapy induced minimal apoptotic effects and G2/M phase arrest in osteosarcoma cells and irradiation alone induced moderate apoptosis and G2/M phase arrest. However, radiation combined with olaparib significantly increased the percentage of apoptotic cells and G2/M phase arrest in osteosarcoma cells (P < 0.05). Immunofluorescence experiments showed that compared to the radiation group, the formation of γ-H2AX and 53BP1 foci was significantly increased in the combined group (P < 0.05). The expression levels of Rad51 foci in the irradiated group were higher than those in the control group (P < 0.05). However, the number of Rad51 foci in the combined group was significantly decreased (P < 0.05). Conclusion: The PARP inhibitor olaparib combined with irradiation (X-rays or C-ions) enhanced the radiosensitivity of osteosarcoma cell lines (U2OS and K7M2). Our findings provide a potential theoretical basis for the clinical application of olaparib in overcoming radiation resistance in osteosarcoma.

Влияние антропогенных факторов на активность клещей семейства Ixodidae: история исследований в России

While studying the characteristics of the formation and existence of foci of transmissible tick-borne infections, it is essential to consider both natural and anthropogenic factors. The impact of human activity on this process undoubtedly requires constant attention. Retrospective studies conducted in our country and the post-Soviet space within this framework are systematized in this review according to the following periodization: the observation and knowledge accumulation stage; the fundamental research enhancement stage; and the contemporary stage. The review provides a characterization and trend analysis of studies on the anthropogenic impact on populations of ticks from the Ixodidae family, highlighting the most significant scientific works and results obtained on the subject. The concluding section emphasizes the importance of accumulating and structuring research to ensure the epidemiological well-being of the population.

Experimental study of the influence of phenozanic acid and its combination with valproic acid on the development of the epileptic system

To study the effect of phenosanic acid (PA) and its combination with valproic acid (VA) on the development of the Epi system. A model of focal chronic epilepsy in rats was created by applying metallic cobalt to the surface of the sensorimotor area of the cortex. Long-term electrodes were implanted in the sensorimotor cortex of the left and right hemispheres, the hippocampus, and the hypothalamus. The effect of PA (80 mg/kg) and its combination with VA (200 mg/kg) on discharge activity was carried out on the 2nd day and at the stage of generalization of the Epi system - on the 6th day. The stability of the Epi system on day 10 was assessed by provoking the development of epileptic status (Epi status) in response to the administration of thiolactone homocysteine (HMC) at a dose of 5.5 mmol/kg. In rats treated with PA, low discharge activity is observed, which is confirmed by the absence of EEG and motor manifestations of status epilepticus caused by HMC. PA does not suppress paroxysmal activity at the stages of development of the Epi system. VA significantly suppresses paroxysmal activity, but does not affect the formation of new foci of Epi activity in subcortical structures and the contralateral cortex. The epi system of rats treated with VA is characterized by high discharge activity by the 10th day of the experiment and lability to provocation of epi status. The combination of drugs is more pronounced than PA, but less than VA, reduces the numerical characteristics of paroxysmal activity in the brain structures of rats. PA when administered alone, in combination with VA, causes a slowdown in the generalization of convulsive foci of Epi activity and prevents the formation of a stable Epi system. VA, having a pronounced anticonvulsant effect, does not weaken the development of the Epi system in the model of focal cobalt-induced epilepsy.