27 research outputs found

    Sensitivity of antibiotic resistant coagulase-negative staphylococci to antiseptic piсloxydin

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    Background. Coagulase-negative staphylococci (CNS), primarily Staphylococcus epidermidis, predominate in the normal microflora of the eye. However, due to irrational antibiotic therapy, resistant strains are widely distributed among CNS. Aim. To study the sensitivity of the antibiotic resistant CNS isolates to picloxydine, an antiseptic. Methods. The species, sensitivity to antibiotics and picloxydine were determined for 39 isolates of bacteria obtained from the conjunctival swabs. The cells morphology under the antiseptics influence was studied by electron microscopy. Results. 33 isolates of S. epidermidis (17 sensitive or resistant to drugs of no more than 2 classes of antibiotics and 16 MDR), 2 S. haemolyticus (1 resistant to 2 classes of antibiotics and 1 MDR), 3 S. hominis (1 sensitive and 2 MDR), 1 S. caprae (MDR) were characterized. In in vitro tests, picloxydine showed high efficiency in suppressing the growth of staphylococci regardless of their sensitivity to antibiotics, as well as bactericidal activity at concentrations of 15.631.2 g/ml, close to those of chlorhexidine. At these concentrations, the antiseptic had a destructive effect on the surface structures of bacterial cells. Conclusion. The picloxydine antiseptic is equally effective against antibiotic- sensitive and antibiotic-resistant coagulase-negative staphylococci

    Genome Digging: Insight into the Mitochondrial Genome of Homo

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    A fraction of the Neanderthal mitochondrial genome sequence has a similarity with a 5,839-bp nuclear DNA sequence of mitochondrial origin (numt) on the human chromosome 1. This fact has never been interpreted. Although this phenomenon may be attributed to contamination and mosaic assembly of Neanderthal mtDNA from short sequencing reads, we explain the mysterious similarity by integration of this numt (mtAncestor-1) into the nuclear genome of the common ancestor of Neanderthals and modern humans not long before their reproductive split.Exploiting bioinformatics, we uncovered an additional numt (mtAncestor-2) with a high similarity to the Neanderthal mtDNA and indicated that both numts represent almost identical replicas of the mtDNA sequences ancestral to the mitochondrial genomes of Neanderthals and modern humans. In the proteins, encoded by mtDNA, the majority of amino acids distinguishing chimpanzees from humans and Neanderthals were acquired by the ancestral hominins. The overall rate of nonsynonymous evolution in Neanderthal mitochondrial protein-coding genes is not higher than in other lineages. The model incorporating the ancestral hominin mtDNA sequences estimates the average divergence age of the mtDNAs of Neanderthals and modern humans to be 450,000-485,000 years. The mtAncestor-1 and mtAncestor-2 sequences were incorporated into the nuclear genome approximately 620,000 years and 2,885,000 years ago, respectively.This study provides the first insight into the evolution of the mitochondrial DNA in hominins ancestral to Neanderthals and humans. We hypothesize that mtAncestor-1 and mtAncestor-2 are likely to be molecular fossils of the mtDNAs of Homo heidelbergensis and a stem Homo lineage. The d(N)/d(S) dynamics suggests that the effective population size of extinct hominins was low. However, the hominin lineage ancestral to humans, Neanderthals and H. heidelbergensis, had a larger effective population size and possessed genetic diversity comparable with those of chimpanzee and gorilla

    Cationic Antiseptics Facilitate Pore Formation in Model Bacterial Membranes

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    Antiseptics are an essential line of defense against bacterial and viral infections in modern medical practice. Many of them are supposed to act on microbial membranes. However, the detailed mechanisms of their action are still elusive. Here, we utilized coarse-grained molecular dynamics simulations to investigate interactions of different types of cationic antiseptics (CAs) with a model bacterial membrane. The simulations revealed qualitatively distinct patterns of dynamic and structural alterations of membrane induced by different types of antiseptics although none of them caused disintegration or solubilization of the bilayer even at the highest explored concentration. At the same time, the adsorption of antiseptics rendered membranes more vulnerable to poration under exposure to the external electric field. We further discuss the possible relation of the enhanced pore formation induced by CAs to their cytotoxic action

    Fluorescent measurements of the endotoxin adsorption efficiency

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    We present the technique for the measurement the LPS statical adsorption on the particles in the area of relatively low concentrations. Direct photon count allows us to detect LPS concentration securely from 100 pM. Using this technique we demonstrate how preequilibration pH affects the results. Raw adsorption data sufficient for building adsorption isotherm is also presented for two sorbents

    The change of foreign trade structure of African countries in the context of increasing regionalization in the world economy

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    Growing interest of international and Russian business in the cooperation with modern Africa and the strengthening of the developing countries' positions in the world brought us to explore the foreign trade of African countries. The research aims to identify trends and new segments for the development of economic relations. We hypothesise that, despite the difficulties in national development, African countries has managed to create areas of successful development by changing the foreign trade structure under the influence of regionalization. The research is based on statistics gathered from international organisations, including the United Nations Economic Commission for Africa, African Development Bank Group, and foreign trade statistics from Côte d'Ivoire. We used the academic literature in the field of foreign trade as the methodological base. The article analysed all types of foreign trade structure (geographical, territorial, organisational, and commodity ones) simultaneously at the global, regional and country levels. As a result of the analysis at the global level, we created a classification of African countries, which identified groups with positive changes in foreign trade structure. Thus, such countries can become leaders in the modern international cooperation. The analysis at the regional level determined some regional integration groups belonging to the category of "growth platforms". The main research result at the country level (on the example of Côte d'Ivoire) is the authors' typology of internal districts. It allowed us to identify "core-regions" and "growing regions" and offer them as perspective points of interaction. These results can be used for economic cooperation with Africa in the framework of implementing the decisions of the "Russia-Africa" summit and economic forum (October 24, 2019, Russian Federation). © 2020 Institute of Economics, Ural Branch of the Russian Academy of Sciences. All rights reserved.The article has been prepared with the support of “5–100” Project in RUDN University, and the Embassy of the Republic of Côte d’Ivoire in the Russian Federation under the agreement on scientific and educational cooperation between RUDN University (Moscow, Russia) and Université Internationale de Cocody (Abidjan, Côte d’Ivoire)

    An equitable vaccine delivery system: Lessons from the COVID-19 vaccine rollout in Canada.

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    BackgroundThe COVID-19 pandemic exacerbated existing health disparities and disproportionately affected vulnerable individuals and communities (e.g., low-income, precariously housed or in institutional settings, racialized, migrant, refugee, 2SLBGTQ+). Despite their higher risk of infection and sub-optimal access to healthcare, Canada's COVID-19 vaccination strategy focused primarily on age, as well as medical and occupational risk factors.MethodsWe conducted a mixed-methods constant comparative qualitative analysis of epidemiological data from a national database of COVID-19 cases and vaccine coverage in four Canadian jurisdictions. Jurisdictional policies, policy updates, and associated press releases were collected from government websites, and qualitative data were collected through 34 semi-structured interviews of key informants from nine Canadian jurisdictions. Interviews were coded and analyzed for themes and patterns.ResultsCOVID-19 vaccines were rolled out in Canada in three phases, each accompanied by specific challenges. Vaccine delivery systems typically featured large-venue mass immunization sites that presented a variety of barriers for those from vulnerable communities. The engagement and targeted outreach that featured in the later phases were driven predominantly by the efforts of community organizations and primary care providers, with limited support from provincial governments.ConclusionsWhile COVID-19 vaccine rollout in Canada is largely considered a success, such an interpretation is shaped by the metrics chosen. Vaccine delivery systems across Canada need substantial improvements to ensure optimal uptake and equitable access for all. Our findings suggest a more equitable model for vaccine delivery featuring early establishment of local barrier-free clinics, culturally safe and representative environment, as well as multi-lingual assistance, among other vulnerability-sensitive elements

    HYDROCARBON POLLUTION IN THE NORTH-WESTERN PART OF THE CASPIAN SEA

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    Aim. The paper is aimed to estimate the current level of hydrocarbon pollution of the marine environment in the North-Western part of the Caspian Sea.Methods. The paper discusses the results of three-year studies conducted in 2012-2014 within the framework of Roshydromet’s Programme of monitoring of transboundary waters of the Caspian Sea. Spatial distribution of concentrations of hydrocarbons (total and polyaromatic) in water and bottom sediments of the area was analysed. Concentrations of total hydrocarbons were determined by means of infrared spectrometry and PAHs – of gas chromatography with mass spectrometry.Results. The range of the total hydrocarbons in the area’s water is from slight traces to 240 µg/l, in sediments – from traces to 114 µg/g (dry weight). Total concentrations of PAHs in water varied from traces to 321 ng/l, in sediments – from traces to 699 ng/g (dry weight). For the source identification, data of satellite monitoring of the area were used. The data showed increasing input of hydrocarbons coming into the marine environment with discharges from vessels.Conclusion. The results of these studies are compared to those of previous research and show that the level of hydrocarbons in the area is typical for slightly polluted areas

    Efficacy of proteolytic therapy in the comprehensive management of patients with second-degree intrauterine synechia

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    Introduction. The article discusses the possibilities of comprehensive management for patients with Asherman’s syndrome.Objective: to describe the experience in comprehensive management of patients with Asherman’s syndrome using an enzymatic proteolytic agent – bovgyaluronidase azoximer.Material and methods. A total of 43 patients with Asherman’s syndrome were examined. The examination methods included transvaginal ultrasound (TVUS), hysteroscopy, intrauterine dissection of synechia, endometrial histopathological examination, IL-6, IL-10, VEGF-A and TGFβ1 test in cervical mucus. The treatment included hysteroscopy, dissection of intrauterine synechia and use of Longidaza I.M. at a dose of 3000 IU once every three days for the course – 5 injections followed up by 1 supposidoitory (3000 ME) intravaginally once every two days for the course – 15 applications) on the top of already administered cyclic estrogen gestagen therapy.Results. A statistically significant reduction of anti-inflammatory index (AII) and TGFβ1/VEGF-A ratio in cervical mucus up to the test results of healthy women of reproductive age (controls) was observed in assessing changes in the local immunological status in patients with Asherman’s syndrome under pressure of azoximer bovgioluronidase therapy after 6 months of observation. AII – 0.68 (0.02) c.u. Group 1 against 0.65 (0.03) c.u. (in control), p = 0.87 and TGFβ1/VEGF-A – 1.8 (0.3) c.u. against 1.4 (0.2) c.u. accordingly, p = 0.84.Сonclusions. Analysis of clinical efficacy of azoximer bovgyaluronidase in the comprehensive management of 21 women with second-grade intrauterine synechia showed recovery of menstrual cycle in 18/21 (85.7%) patients, relief of menstrual pain in 11/21 (52.3%) patients. 6/21 (28.5%) patients with infertility and 2/21 (9.5%) patients with miscarriage obtained spontaneous pregnancy 12 months after the therapy. All pregnancies ended in term births

    What binds cationic photosensitizers better: Brownian dynamics reveals key interaction sites on spike proteins of sars-cov, mers-cov, and sars-cov-2

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    We compared the electrostatic properties of the spike proteins (S-proteins) of three coronaviruses, SARS-CoV, MERS-CoV, and SARS-CoV-2, and their interactions with photosensitizers (PSs), octacationic octakis(cholinyl)zinc phthalocyanine (Zn-PcChol8+) and monocationic methylene blue (MB). We found a major common PS binding site at the connection of the S-protein stalk and head. The molecules of Zn-PcChol8+ and MB also form electrostatic encounter complexes with large area of negative electrostatic potential at the head of the S-protein of SARS-CoV-2, between fusion protein and heptad repeat 1 domain. The top of the SARS-CoV spike head demonstrates a notable area of electrostatic contacts with Zn-PcChol8+ and MB that corresponds to the N-terminal domain. The S-protein protomers of SARS-CoV-2 in “open” and “closed” conformations demonstrate different ability to attract PS molecules. In contrast with Zn-PcChol8+, MB possesses the ability to penetrate inside the pocket formed as a result of SARS-CoV-2 receptor binding domain transition into the “open” state. The existence of binding site for cationic PSs common to the S-proteins of SARS-CoV, SARS-CoV-2, and MERS-CoV creates prospects for the wide use of this type of PSs to combat the spread of coronaviruses. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
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