Effects of lead oxide nanoparticles on myelin sheaths inthe rat brain

The aim of the study - to evaluate effects of intranasal exposure to lead oxide nanoparticles on myelin sheaths in the rat brain.Цель исследования – оценить воздействие наночастиц оксида свинца на миелиновые оболочки мозга крыс после интраназальной экспозиции

Features of penetration of lead oxide nanoparticles into the rat brain

The aim of the study – to examine PbO NPs penetration into the brain.Цель исследования – изучение особенностей проникновения наночастиц оксида свинца (НЧ PbO) в головной моз

Analysis of Experimental Data on Changes in Various Structures and Functions of the Rat Brain following Intranasal Administration of Fe2O3 Nanoparticles

Particulate matter, including iron nanoparticles, is one of the constituents of ambient air pollution. We assessed the effect of iron oxide (Fe2O3) nanoparticles on the structure and function of the brain of rats. Electron microscopy showed Fe2O3 nanoparticles in the tissues of olfactory bulbs but not in the basal ganglia of the brain after their subchronic intranasal administration. We observed an increase in the number of axons with damaged myelin sheaths and in the proportion of pathologically altered mitochondria in the brains of the exposed animals against the background of almost stable blood parameters. We conclude that the central nervous system can be a target for toxicity of low-dose exposure to Fe2O3 nanoparticles. © 2023 by the authors.Ministry of Education and Science of the Russian Federation, Minobrnauka; Ural Federal University, UrFUThe analysis was supported by the Ministry of Science and Higher Education of the Russian Federation within the “Priority—2030” Development Program of the Ural Federal University; the experimental data were provided by Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers

Electron microscopy study on the transport of lead oxide nanoparticles into brain structures following their subchronic intranasal administration in rats

White outbred female rats were exposed intranasally to 50-µL of suspension of lead oxide nanoparticles (PbO NPs) at a concentration of 0.5 mg/mL thrice a week during six weeks. A control group of rats was administered deionized water in similar volumes and conditions. The developed intoxication was manifested by altered biochemical and cytochemical parameters, as well as behavioral reactions of animals. Using electron microscopy and energy-dispersive X-ray spectroscopy techniques, we revealed deposition of PbO NPs in the olfactory bulb, but not in basal ganglia, and an increase in the number of axons with damage to the myelin sheath in the tissues of olfactory bulb and basal ganglia, changes in the ultrastructure of mitochondria of neurons in the tissues of olfactory bulb and basal ganglia of the brain, and differences in the mitochondrial profile of neurons in different regions of the rat brain. Our results collectively suggest that the central nervous system may be a target of low-level toxicity of lead oxide nanoparticles. © 2022, The Author(s).Ural Federal University Program of DevelopmentYekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial WorkersMinistry of Education and Science of the Russian Federation, MinobrnaukaThe research funding from Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers for funding the experimental materials and facilities is gratefully acknowledged. The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority–2030 Program) for experiment implementation and analysis of its results is gratefully acknowledged

Features of the response to subchronic low-dose exposure to copper oxide nanoparticles in rats

Copper is an essential trace element for human health and, at the same time, a major industrial metal widely used both in its elemental form and in compounds. We conducted a dose-dependent assessment of the response of outbred albino male rats to subchronic low-dose exposure to copper oxide nanoparticles administered intraperitoneally at cumulative doses of 18 and 36 mg/kg during 6 weeks to exposure groups 1 and 2, respectively. We observed disorders at different levels of organization of the body in the exposed animals, from molecular to organismal. The observed decrease in the activity of succinate dehydrogenase in nucleated blood cells gave evidence of impaired bioenergetics processes. In view of the results of the metabolomics analysis, we assume mitochondrial damage and contribution of apoptotic processes to the pathology induced by copper poisoning. We also assume neurodegenerative effects based on the assessed morphological parameters of the nervous system, results of behavioral tests, and a decreased level of expression of genes encoding NMDA receptor subunits in the hippocampus. The hepatotoxic effect noted by a number of metabolomics-based, biochemical, and cytological indicators was manifested by the impaired protein-synthesizing function of the liver and enhanced degenerative processes in its cells. We also observed a nephrotoxic effect of nanosized copper oxide with a predominant lesion of proximal kidney tubules. At the same time, both doses tested demonstrated such positive health effects as a statistically significant decrease in the activity of alkaline phosphatase and the nucleated blood cell DNA fragmentation factor. Judging by the changes observed, the cumulative dose of copper oxide nanoparticles of 18 mg/kg body weight administered intraperitoneally approximates the threshold one for rats. The established markers of health impairments may serve as a starting point in the development of techniques of early diagnosis of copper poisoning. © 2023, The Author(s).Friedrich-Schiller-Universität Jena, FSU; Ministry of Education and Science of the Russian Federation, Minobrnauka; Ministry of Science and Higher Education of the Russian Federation: Priority – 2030Open Access funding enabled and organized by Projekt DEAL. The research funding from Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers for funding the experimental materials and facilities is gratefully acknowledged. The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority–2030 Program) for experiment implementation and analysis of its results is gratefully acknowledged. The authors would like to express their deepest gratitude to the staff of the Ural Center for Shared Use “Modern Nanotechnologies” of the Ural Federal University named after the First Russian President Boris Yeltsin and personally to Professor Vladimir Ya. Shur, Director of the Center, for invaluable support in conducting this study by synthesizing suspensions of the nanoparticles studied. We are also grateful to the staff of the Central Research Laboratory of the Ural State Medical University and personally to Professor Oleg G. Makeyev for establishing genomic DNA fragmentation

Invasive fungal infections in neutropenic enterocolitis: A systematic analysis of pathogens, incidence, treatment and mortality in adult patients

BACKGROUND: Neutropenic enterocolitis is a life-threatening complication most frequently occurring after intensive chemotherapy in acute leukaemias. Gramnegative bacteria constitute the most important group of causative pathogens. Fungi have also been reported, but their practical relevance remains unclear. The guidelines do not address concrete treatment recommendations for fungal neutropenic enterocolitis. METHODS: Here, we conducted a metaanalysis to answer the questions: What are frequency and mortality of fungal neutropenic enterocolitis? Do frequencies and microbiological distribution of causative fungi support empirical antimycotic therapy? Do reported results of antimycotic therapy in documented fungal neutropenic enterocolitis help with the selection of appropriate drugs? Following a systematic search, we extracted and summarised all detail data from the complete literature. RESULTS: Among 186 articles describing patients with neutropenic enterocolitis, we found 29 reports describing 53 patients with causative fungal pathogens. We found no randomised controlled trial, no good quality cohort study and no good quality case control study on the role of antifungal treatment. The pooled frequency of fungal neutropenic enterocolitis was 6.2% calculated from all 860 reported patients and 3.4% calculated from selected representative studies only. In 94% of the patients, Candida spp. were involved. The pooled mortality rate was 81.8%. Most authors did not report or perform antifungal therapy. CONCLUSION: In patients with neutropenic enterocolitis, fungal pathogens play a relevant, but secondary role compared to bacteria. Evidence concerning therapy is very poor, but epidemiological data from this study may provide helpful clues to select empiric antifungal therapy in neutropenic enterocolitis

Low‐carbon transition risks for finance

The transition to a low‐carbon economy will entail a large‐scale structural change. Some industries will have to expand their relative economic weight, while other industries, especially those directly linked to fossil fuel production and consumption, will have to decline. Such a systemic shift may have major repercussions on the stability of financial systems, via abrupt asset revaluations, defaults on debt, and the creation of bubbles in rising industries. Studies on previous industrial transitions have shed light on the financial transition risks originating from rapidly rising “sunrise” industries. In contrast, a similar conceptual understanding of risks from declining “sunset” industries is currently lacking. We substantiate this claim with a critical review of the conceptual and historical literature, which also shows that most literature either examines structural change in the real economy, or risks to financial stability, but rarely both together. We contribute to filling this research gap by developing a consistent theoretical framework of the drivers, transmission channels, and impacts of the phase‐out of carbon‐intensive industries on the financial system and on the feedback from the financial system into the rest of the economy. We also review the state of play of policy aiming to protect the financial system from transition risks and spell out research implications

Securitization and the Fixed-Rate Mortgage

Fixed-rate mortgages (FRMs) dominate the U.S. mortgage market, with important consequences for household risk management, monetary policy, and systemic risk. In this paper, we show that securitization is a key driver of FRM supply. Our analysis compares the agency and nonagency mortgage-backed-securities (MBS) markets, exploiting the freeze in nonagency MBS liquidity in the third quarter of 2007. Using exogenous variation in access to the agency MBS market, we find that when both market segments are liquid they perform similarly in terms of supporting FRM supply. However, after the nonagency market freezes, the share of FRMs is sharply higher among mortgages eligible to be securitized through the still-liquid agency MBS market. Our interpretation is that securitization is particularly important for FRMs because of the prepayment and interest rate risk embedded in these loans. We highlight policy implications for ongoing reform of the U.S. mortgage finance system