Publications by authors named "Alexandrova L"

The short-chain fatty acids (SCFAs) propionate and butyrate have beneficial health effects, are produced in large amounts by microbial metabolism and have been identified as unique acyl lysine histone marks. To better understand the function of these modifications, we used chromatin immunoprecipitation followed by sequencing to map the genome-wide location of four short-chain acyl histone marks, H3K18pr, H3K18bu, H4K12pr and H4K12bu, in treated and untreated colorectal cancer (CRC) and normal cells as well as in mouse intestines in vivo. We correlate these marks with open chromatin regions and gene expression to access the function of the target regions.

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To design a safe cellular system for testing inhibitors targeting the RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2, a genetic construct was engineered containing viral cDNA with two blocks of reporter genes while the genes encoding structural S, E, and M proteins were absent. The first reporter block, consisting of Renilla luciferase and green fluorescent protein (Rluc-GFP), was located upstream of the SARS-CoV-2 5'-UTR. Meanwhile, the second block represented by firefly luciferase and red fluorescent protein (Fluc-RFP) was positioned downstream of the transcription regulatory sequence (TRS-N).

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The mechanisms of action of pyrimidine nucleoside derivatives on model lipid membranes of various compositions were studied. A systematic analysis of the tested agents' effects on the membrane physicochemical properties was performed. Differential scanning microcalorimetry data indicated that the ability of nucleoside derivatives to disorder membrane lipids depended on the types of nucleoside bases and membrane-forming lipids.

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A series of polyimides (PIs) was synthesized from 6FDA and two -OH substituted diamines having bulky pendant phenyl, Ph, and trifluoromethyl, CF, groups as precursors for thermally rearranged polybenzoxazole, TR-PBO, membranes. One diamine had two pendant Ph substituents; in the other, the substituents were Ph and CF. Applying azeotropic and chemical cyclizations allowed the obtention of four -hydroxy (-OH) or/and -acetoxy (-OAc) substituted PIs depending on the imidization method.

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Purpose: Triple-negative breast cancer (TNBC) often metastasizes to the central nervous system (CNS) and has the highest propensity among breast cancer subtypes to develop leptomeningeal disease (LMD). LMD is a spread of cancer into leptomeningeal space that speeds up the disease progression and severely aggravates the prognosis. LMD has limited treatment options.

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The rapid increase in the antibiotic resistance of microorganisms, capable of causing diseases in humans as destroying cultural heritage sites, is a great challenge for modern science. In this regard, it is necessary to develop fundamentally novel and highly active compounds. In this study, a series of -alkylcytidines, including 5- and 6-methylcytidine derivatives, with extended alkyl substituents, were obtained in order to develop a new generation of antibacterial and antifungal biocides based on nucleoside derivatives.

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Purpose: Triple-negative breast cancer (TNBC) is an aggressive subtype that often metastasizes to the brain. Leptomeningeal disease (LMD), a devastating brain metastasis common in TNBC, has limited treatment options. We sought to test whether the common anti-helminthic drug mebendazole (MBZ) may be effective against murine TNBC LMD.

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The short-chain fatty acids (SCFA) propionate and butyrate have beneficial health effects, are produced in large amounts by microbial metabolism and have been identified as unique acyl lysine histone marks. In order to better understand the function of these modifications we used ChIP-seq to map the genome-wide location of four short-chain acyl histone marks H3K18pr, H3K18bu, H4K12pr and H4K12bu in treated and untreated colorectal cancer (CRC) and normal cells, as well as in mouse intestines . We correlate these marks with open chromatin regions along with gene expression to access the function of the target regions.

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To date, there are no approved treatments for the diminished strength and paralysis that result from the loss of peripheral nerve function due to trauma, heritable neuromuscular diseases, or aging. Here, we showed that denervation resulting from transection of the sciatic nerve triggered a marked increase in the prostaglandin-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in skeletal muscle in mice, providing evidence that injury drives early expression of this aging-associated enzyme or gerozyme. Treating mice with a small-molecule inhibitor of 15-PGDH promoted regeneration of motor axons and formation of neuromuscular synapses leading to an acceleration in recovery of force after an acute nerve crush injury.

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The emergence of drug-resistant strains of pathogenic microorganisms necessitates the creation of new drugs. A series of uridine derivatives containing an extended substituent at the C-5 position as well as C-5 alkyloxymethyl, alkylthiomethyl, alkyltriazolylmethyl, alkylsulfinylmethyl and alkylsulfonylmethyl uridines were obtained in order to explore their antimicrobial properties and solubility. It has been shown that new ribonucleoside derivatives have an order of magnitude better solubility in water compared to their 2'-deoxy analogues and effectively inhibit the growth of a number of Gram-positive bacteria, including resistant strains of Mycobacterium smegmatis (MIC=15-200 μg/mL) and Staphylococcus aureus (MIC=25-100 μg/mL).

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The influence of trifluoromethanesulfonic (TFSA) superacid on conditions of the synthesis of polybenzimidazoles, such as OPBI and CFPBI, was studied. It was shown that the polycondensations proceeded smoother and at lower temperatures in the presence of the TFSA in Eaton's Reagent and that polymers of high molecular weights, and readily soluble in organic solvents, were obtained. The effect was more pronounced for CFPBI, where the low reactivity monomer, 4,4' (hexafluoroisoproylidene)bis (benzoic acid), was used.

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Tuberculosis (TB) is the oldest human infection disease. Mortality from TB significantly decreased in the 20th century, because of vaccination and the widespread use of antibiotics. However, about a third of the world's population is currently infected with () and the death rate from TB is about 1.

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Unlabelled: In connection with the ongoing pandemic of the novel coronavirus infection, the study of its morphopathology and the analysis of autopsy data are relevant. At the same time, attention should be paid to thromboses that play a significant role in the development of fatal outcomes in COVID-19, even taking into account the prescription of anticoagulant therapy to most patients.

Objective: To make an assessment of morphological changes and a statistical analysis of the structure of mortality in COVID-19 on the basis of autopsy results in the Volgograd Region in 2020.

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The Aim Of The Study Was To Analyze: The impact of morphological and functional dental components on the quality of life of adult patients undergoing orthodontic treatment using clear aligners.

Materials And Methods: Morphological and functional results of orthodontic treatment with aligners as well as the dynamics of oral health related quality of life was assessed in 55 patients aged from 20 to 25 years.

Results: The study of the efficacy of orthodontic treatment with aligners showed significant improvement of morphological and functional features of dental arches as well as oral health related quality of life in the course of treatment.

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The emergence of drug-resistant strains of pathogenic microorganisms necessitates the creation of new drugs. In order to find new compounds that effectively inhibit the growth of pathogenic bacteria and fungi, we synthesized a set of N-derivatives of cytidine, 2'-deoxycytidine and 5-metyl-2'-deoxycytidine bearing extended N-alkyl and N-phenylalkyl groups. The derivatives demonstrate activity against a number of Gram-positive bacteria, including Mycobacterium smegmatis (MIC = 24-200 μM) and Staphylococcus aureus (MIC = 50-200 μM), comparable with the activities of some antibiotics in medical use.

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Resistance developed to the majority of drugs used to treat infectious diseases warrants the design of new compounds effective against drug-resistant strains of pathogens. Recently, several groups of modified nucleosides have been synthesized and showed significant antibacterial activity in vitro, but their further studies were difficult to undertake because of their low solubility in aqueous solutions. Nevertheless, new compounds, well soluble in water-organic solutions, were synthesized and found to be more effective in inhibiting the growth of Gram-positive bacteria and mycobacteria.

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Treatments are lacking for sarcopenia, a debilitating age-related skeletal muscle wasting syndrome. We identifed increased amounts of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), the prostaglandin E (PGE)-degrading enzyme, as a hallmark of aged tissues, including skeletal muscle. The consequent reduction in PGE signaling contributed to muscle atrophy in aged mice and results from 15-PGDH-expressing myofibers and interstitial cells, such as macrophages, within muscle.

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Article Synopsis
  • The rapid growth of the global population and new energy technologies is driving unprecedented energy consumption and depleting fossil fuel reserves, necessitating cleaner energy solutions.
  • Proton exchange membrane (PEM) fuel cells are emerging as a promising alternative energy source, particularly those using polybenzimidazole (PBI)-based polymers.
  • This review summarizes recent advances in PBI composite membranes for high-temperature PEM fuel cells and discusses the challenges, future trends, and potential for these materials as solid electrolytes.
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In this paper, a series of composite proton exchange membranes comprising a cobaltacarborane protonated H[Co(C2B9H11)2] named (H[COSANE]) and polybenzimidazole (PBI) for a high temperature proton exchange membrane fuel cell (PEMFC) is reported, with the aim of enhancing the proton conductivity of PBI membranes doped with phosphoric acid. The effects of the anion [Co(C2B9H11)2] concentration in three different polymeric matrices based on the PBI structure, poly(2,2'-(m-phenylene)-5,5'-bibenzimidazole) (PBI-1), poly[2,2'-(p-oxydiphenylene)-5,5'-bibenzimidazole] (PBI-2) and poly(2,2'-(p-hexafluoroisopropylidene)-5,5'-bibenzimidazole) (PBI-3), have been investigated. The conductivity, diffusivity and mobility are greater in the composite membrane poly(2,2'-(p-hexafluoroisopropylidene)-5,5'-bibenzimidazole) containing fluorinated groups, reaching a maximum when the amount of H[COSANE] was 15%.

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A fundamental, clinical, and scientific concern is how lytic bacteriophage, as well as antibiotics, impact diagnostic positivity. Cholera was chosen as a model disease to investigate this important question, because cholera outbreaks enable large enrollment, field methods are well established, and the predatory relationship between lytic bacteriophage and the etiologic agent share commonalities across bacterial taxa. Patients with diarrheal disease were enrolled at two remote hospitals in Bangladesh.

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Multi-stage therapy of children with congenital diseases of the maxillofacial region requires a multidisciplinary team of specialists coordinated consistently conducted treatment, not only providing a complete reconstruction of the maxillary bones, but also improving the quality of life of children. In our study, it was found that the most significant independent predictors of the total indicator of quality of life are indicators of structures and functions of the maxillofacial region, as well as the level of activity and participation of children in real life situations and the level of parental compliance.

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The data of transmission electron microscopy (TEM) on morphology of M. tuberculosis H37Rv bacterial cells treated with four analogues of pyrimidine nucleosides with different substituents at 5 position of base are presented. We showed that the growth of M.

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Recently we have synthesized a set of pyrimidine nucleoside derivatives bearing extended alkyltriazolylmethyl substituents at position 5 of the nucleic base, and showed their significant activity against Mycobacterium tuberculosis virulent laboratory strain H37Rv as well as drug-resistant MS-115 strain. The presence of a lengthy hydrophobic substituent leads to the reduction of nucleoside water solubility making their antibacterial activity troublesome to study. A series of water-soluble forms of 5-modified 2'-deoxyuridines 4a-c and 8a-c were synthesized.

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Background: A first step to combating antimicrobial resistance in enteric pathogens is to establish an objective assessment of antibiotic exposure. Our goal was to develop and evaluate a liquid chromatography-ion trap mass spectrometry (LC/MS) method to determine antibiotic exposure in patients with cholera.

Methods: A priority list for targeted LC/MS was generated from medication-vendor surveys in Bangladesh.

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